Mercuriceratops gemini (center) compared to horned dinosaurs Centrosaurus (left) and Chasmosaurus (right), also from the Dinosaur Park Formation of Alberta, Canada. Credit: Courtesy Danielle Dufault
Scientists have named a new species of horned dinosaur (ceratopsian) based on fossils collected from Montana in the United States and Alberta, Canada. Mercuriceratops (mer-cure-E-sare-ah-tops) gemini was approximately 6 meters (20 feet) long and weighed more than 2 tons. It lived about 77 million years ago during the Late Cretaceous Period. Research describing the new species is published online in the journal Naturwissenschaften.
Mercuriceratops (Mercuri + ceratops) means “Mercury horned-face,” referring to the wing-like ornamentation on its head that resembles the wings on the helmet of the Roman god, Mercury. The name “gemini” refers to the almost identical twin specimens found in north central Montana and the UNESCO World Heritage Site, Dinosaur Provincial Park, in Alberta, Canada. Mercuriceratops had a parrot-like beak and probably had two long brow horns above its eyes. It was a plant-eating dinosaur.
“Mercuriceratops took a unique evolutionary path that shaped the large frill on the back of its skull into protruding wings like the decorative fins on classic 1950s cars. It definitively would have stood out from the herd during the Late Cretaceous,” said lead author Dr. Michael Ryan, curator of vertebrate paleontology at The Cleveland Museum of Natural History. “Horned dinosaurs in North America used their elaborate skull ornamentation to identify each other and to attract mates — not just for protection from predators. The wing-like protrusions on the sides of its frill may have offered male Mercuriceratops a competitive advantage in attracting mates.”
“The butterfly-shaped frill, or neck shield, of Mercuriceratops is unlike anything we have seen before,” said co-author Dr. David Evans, curator of vertebrate palaeontology at the Royal Ontario Museum. “Mercuriceratops shows that evolution gave rise to much greater variation in horned dinosaur headgear than we had previously suspected.”
The new dinosaur is described from skull fragments from two individuals collected from the Judith River Formation of Montana and the Dinosaur Park Formation of Alberta. The Montana specimen was originally collected on private land and acquired by the Royal Ontario Museum. The Alberta specimen was collected by Susan Owen-Kagen, a preparator in Dr. Philip Currie’s lab at the University of Alberta. “Susan showed me her specimen during one of my trips to Alberta,” said Ryan. “I instantly recognized it as being from the same type of dinosaur that the Royal Ontario Museum had from Montana.”
The Alberta specimen confirmed that the fossil from Montana was not a pathological specimen, nor had it somehow been distorted during the process of fossilization,” said Dr. Philip Currie, professor and Canada research chair in dinosaur paleobiology at the University of Alberta. “The two fossils — squamosal bones from the side of the frill — have all the features you would expect, just presented in a unique shape.”
“This discovery of a previously unknown species in relatively well-studied rocks underscores that we still have many more new species of dinosaurs to left to find,” said co-author Dr. Mark Loewen, research associate at the Natural History Museum of Utah.
This dinosaur is just the latest in a series of new finds being made by Ryan and Evans as part of their Southern Alberta Dinosaur Project, which is designed to fill in gaps in our knowledge of Late Cretaceous dinosaurs and study their evolution. This project focuses on the paleontology of some of oldest dinosaur-bearing rocks in Alberta and the neighbouring rocks of northern Montana that are of the same age.
Journal Reference:
Michael J. Ryan, David C. Evans, Philip J. Currie, Mark A. Loewen. A new chasmosaurine from northern Laramidia expands frill disparity in ceratopsid dinosaurs. Naturwissenschaften, 2014; 101 (6): 505 DOI: 10.1007/s00114-014-1183-1
Note : The above story is based on materials provided by Cleveland Museum of Natural History.
Geothermal energy is harvested by pumping cold water down an injection well, and bringing hot water up again via a production well. Left: In areas that produce geothermal energy today, the water flows through natural fractures in the bedrock between the wells, heating up in the process. Right: In future drilling in hard rock that lacks natural cracks, as in Norway, drilling a series of radiating bore-holes between the wells is a possibility. An alternative method is to create such cracks by subjecting the bedrock to extremely high hydraulic pressure (so-called “fracking”). Click Here for large photo Credit: SINTEF/Knut Gangåssæter.
Capturing green energy from deep in the Earth will bring competitive electricity and district heating – with help from Norway.
Ever since Jules Verne’s 1864 novel ” A Journey to the Centre of the Earth”, people have dreamt of capturing the heat of planet Earth. It exists in huge amounts, is completely renewable and emits no CO2.
“What we have done so far is no more than to scratch the surface of the Earth. The heat that many people extract from their gardens and then upgrade in heat pumps is not geothermal, but rather solar energy,” says SINTEF research scientist Alexandre Kane.
Backed by a troop of industrial and technology companies, Kane is manager of the Nextdrill research project, whose members are going ahead at full speed to develop drilling tools that will make it profitable to exploit true geothermal heat.
The immediate aim is to drill wells to depths of five to six kilometres, where we encounter temperatures that are high enough to allow the heat to be used for district heating and electricity generation.
“For this to be commercially viable we will need to drill much more cheaply than the petroleum industry does, and without needing permanent subsidies. At the same time, we need to penetrate bedrock that is much harder than we find on the continental shelf in the North Sea. It may sound as though it will be impossible to do both of these things at once, but we have a great belief in the possibility, as long as research continues along the same lines after this preliminary project has come to an end,” says Kane.
High speed; long working life
As in all drilling operations, the taximeter rises rapidly. If geothermal heat is to be competitive as a source of energy, the time put into drilling must be kept to a minimum. Drilling operators who want to capture this heat therefore need to be able to drill at high speed. Nor can they afford the loss of time involved if the drill-bit is always having to be brought to the surface and replaced.
The Nextdrill project is a response to this challenge. Three of its members – SINTEF, the Swedish company Sandvik and Germany’s H.C. Starck – are collaborating on the development of materials for a drill-bit with a long working life.
Another participant is the Norwegian technology company Resonator, which is in the process of developing an electric percussion rotary drill, a tool that crushes rock by dealing it hammer-like blows as the drill-bit turns. Electrical operation offers the possibility of remote control and more energy-efficient drilling systems than technology based on today’s pneumatic or hydraulic systems.
First test in August
In the course of this year the Nextdrill project will carry out its first small-scale drilling trials near Ås in Akershus County. In August and again in November, a specially designed version of Resonator’s percussion rotary drill will tackle hard rock. It will be fitted in turn with commercially available drill-bits and bits made of the highly wear-resistant materials that are being developed by the project.
These trials have two main purposes. They will provide new knowledge about how wear occurs on drill-bits when rock is crushed using an electric percussion rotary drill. The tests will also show how the number of impacts per unit time affects the speed of drilling.
“Although we will not be drilling very deep during these tests we do expect to gather important data for the next stages of our efforts to develop highly durable materials,” says Kane.
Geothermal energy
The heat that SINTEF’s French project manager wants to capture is known as geothermal energy, and is derived from two sources that lie far beneath our feet. About one third of it is heat that has been stored in the Earth’s molten core since our planet was formed. The other two-thirds have their origin in the decay of radioactive isotopes in the Earth’s crust. This process releases heat, which means that the temperature rises, metre by metre, the further we drill into the interior of the planet.
Two types of well need to be drilled to exploit this heat; one to pump cold water down, and the other to bring hot water up again (see illustration). The drill-bit that does this job must be able to crush hard rock types such as granite. The main aim of the Nextdrill project is to identify a combination of hard-wearing, durable materials and technical solutions that can do this (see fact-sheet).
Laboratory trials and computer models
The drill-bit needs to be able to withstand a high level of friction, in addition to enormous amounts of mechanical abuse resulting from the high-frequency hammer impacts.
“Laboratory trials and virtual experiments performed by computer models have taught us a great deal about drilling through granite, and have enabled us to develop models that we use to find the optimal form and composition of the drill-bit. The drilling trials at Ås will give us measurements that will let us further improve the computer model,” says Kane.
Note : The above story is based on materials provided by SINTEF
Chemical Formula: CaSi2O5·2H2O Locality: Disko Island, Greenland. Poona, near Bombay, India. Name Origin: Named for Lorenz Oken (1779-1851), German natural historian, Munich Germany.
Okenite (CaSi2O5·2H2O) is a silicate mineral that is usually associated with zeolites. It most commonly is found as small white “cotton ball” formations within basalt geodes. These formations are clusters of straight, radiating, fibrous crystals that are both bendable and fragile.
It was first described in 1828 for an occurrence at Disko Island, Greenland and named for German naturalist Lorenz Oken (1779–1851).
Minerals associated with okenite include apophyllite, gyrolite, prehnite, chalcedony, goosecreekite and many of the other zeolites. Okenite is found in India, mainly within the state of Maharashtra. Other localities include Bulla Island, Azerbaijan; Aranga, New Zealand; Chile; Ireland and Bordo Island in the Faroe Islands.
History
Discovery date: 1828 Town of Origin : ILE DISKO Country of Origin: GROENLAND
Physical Properties
Cleavage: {001} Good Color: White, Yellowish white, Bluish white. Density: 2.3 – 2.33, Average = 2.31 Diaphaneity:Transparent to Translucent Fracture: Conchoidal – Fractures developed in brittle materials characterized by smoothly curving surfaces, (e.g. quartz). Hardness: 5 – Apatite Luminescence: Non-Fluorescent. Luster: Pearly Streak: white
It is likely that most of the large impact craters on Earth have already been discovered and that others have been erased, according to a new calculation by a pair of Purdue University graduate students.
“Over the past 3.5 billion years it is thought that more than 80 asteroids similar in size to, or larger than, the one which killed the dinosaurs have struck the Earth, leaving behind craters which are over 100 kilometers across, but our model suggests only about eight of these massive craters could still exist today,” said Timothy Bowling, a graduate student in Purdue’s Department of Earth, Atmospheric and Planetary Sciences. “Geologists have already found six or seven such craters, so odds are not in the favor of those hoping to find the next big crater.”
The movement of the Earth’s tectonic plates and other geologic processes erase craters over time, he said.
“Impact craters dominate the surface of other planets and bodies in our solar system, like the famously pockmarked moon and Mercury, but the Earth looks different,” Bowling said. “The Earth’s crust is very dynamic and active, and over time it pushes and pulls these craters deep below the surface, until eventually they are sunk into the Earth’s mantle and disappear.”
Although it is known that natural processes erase craters fairly quickly from the Earth’s surface, this model was the first to quantify how many craters have likely been erased, he said.
Brandon Johnson, a postdoctoral researcher at the Massachusetts Institute of Technology who at the time was a graduate student at Purdue, led the study, which is to be published in the journal Geology. Both Bowling and Johnson worked under Jay Melosh, a Purdue distinguished professor of earth, atmospheric and planetary sciences and physics. A NASA planetary geology and geophysics grant funded this research.
Bowling and Johnson used the age of the Earth’s terrestrial and oceanic crusts and three different scenarios of Earth’s bombardment history to determine the maximum probability that a crater made a given number of years ago would still exist today. They then estimated the percentage of craters that could persist and be observed today for each of the bombardment scenarios.
The model’s ability to estimate the percentage of large craters that would survive to present day could be useful in supporting or refuting different theories of the ratio of large to small impacts, called the size frequency distribution, Bowling said.
“The number of smaller impacts that would have likely occurred for every large impact we find is a looming question in the field,” he said. “Existing theories are mostly based on studies of craters on the surfaces of other bodies, like the moon. No one had attempted this before using the Earth’s crater record because it couldn’t be done without having an idea of how many craters have been erased. This model could be used to help confirm or refute proposed theories.”
While the model could be applied to studies of the size frequency distribution, it cannot be used to distinguish between different models of the rate at which large objects hit Earth, he said. These models vary from those that expect constant bombardment to those that predict that earlier time periods were responsible for a greater number of impacts.
An ability to accurately determine the date of impact is needed to distinguish between different proposed bombardment scenarios, Bowling said.
Instead of hunting for craters, scientists should search for layers of debris ejected on impact to better understand the Earth’s bombardment history, Bowling said.
When asteroids larger than about 10 kilometers, or six miles, in diameter crash into the Earth a plume of vaporized rock rises into space. Small droplets of this plume condense, solidify and fall back to the surface. A thin layer of these particles, called spherules, then blankets the Earth. This layer of spherules persists in the geologic record and can be used to determine the date of impact. The thickness of the spherule layer and the size of the individual spherules within it also provide information about the asteroid and its size. These spherule layers persist long after the craters have been erased, he said.
More information:
Paper: Where have all the craters gone? Earth’s bombardment history and the expected terrestrial cratering record, Geology, 2014.
Note : The above story is based on materials provided by Purdue University
A sample of the 4.5 billion-year-old Tenham meteorite that contains submicrometer-sized crystals of bridgmanite. Credit: Chi Ma / Caltech
Deep below the earth’s surface lies a thick, rocky layer called the mantle, which makes up the majority of our planet’s volume. For decades, scientists have known that most of the lower mantle is a silicate mineral with a perovskite structure that is stable under the high-pressure and high-temperature conditions found in this region. Although synthetic examples of this composition have been well studied, no naturally occurring samples had ever been found in a rock on the earth’s surface. Thanks to the work of two scientists, naturally occurring silicate perovskite has been found in a meteorite, making it eligible for a formal mineral name.
The mineral, dubbed bridgmanite, is named in honor of Percy Bridgman, a physicist who won the 1946 Nobel Prize in Physics for his fundamental contributions to high-pressure physics.
“The most abundant mineral of the earth now has an official name,” says Chi Ma, a mineralogist and director of the Geological and Planetary Sciences division’s Analytical Facility at Caltech.
“This finding fills a vexing gap in the taxonomy of minerals,” adds Oliver Tschauner, an associate research professor at the University of Nevada-Las Vegas who identified the mineral together with Ma.
High-pressure and temperature experiments, as well as seismic data, strongly suggest that (Mg,Fe)SiO3-perovskite—now simply called bridgmanite—is the dominant material in the lower mantle. But since it is impossible to get to the earth’s lower mantle, located some 400 miles deep within the planet and rocks brought to the earth’s surface from the lower mantle are exceedingly rare, naturally occurring examples of this material had never been fully described.
That is until Ma and Tschauner began poking around a sample from the Tenham meteorite, a space rock that fell in Australia in 1879.
Because the 4.5 billion-year-old meteorite had survived high-energy collisions with asteroids in space, parts of it were believed to have experienced the high-pressure conditions we see in the earth’s mantle. That, scientists thought, made it a good candidate for containing bridgmanite.
Tschauner used synchrotron X-ray diffraction mapping to find indications of the mineral in the meteorite. Ma then examined the mineral and its surroundings with a high-resolution scanning electron microscope and determined the composition of the tiny bridgmanite crystals using an electron microprobe. Next, Tschauner analyzed the crystal structure by synchrotron diffraction. After five years and multiple experiments, the two were finally able to gather enough data to reveal bridgmanite’s chemical composition and crystal structure.
“It is a really cool discovery,” says Ma. “Our finding of natural bridgmanite not only provides new information on shock conditions and impact processes on small bodies in the solar system, but the tiny bridgmanite found in a meteorite could also help investigations of phase transformation mechanisms in the deep Earth. ”
The mineral and the mineral name were approved on June 2 by the International Mineralogical Association’s Commission on New Minerals, Nomenclature and Classification.
Note : The above story is based on materials provided by California Institute of Technology
Chemical Formula: Ni Locality: Bogota, Canala, New Caledonia. Name Origin: From the German Nickel – “demom”, from a contraction of kupfernickel, or “Devil’s Copper”, as the mineral was believed to contain copper but yielded none when smelted.
Nickel is a chemical element with the chemical symbol Ni and atomic number 28. It is a silvery-white lustrous metal with a slight golden tinge. Nickel belongs to the transition metals and is hard and ductile. Pure nickel shows a significant chemical activity that can be observed when nickel is powdered to maximize the exposed surface area on which reactions can occur, but larger pieces of the metal are slow to react with air at ambient conditions due to the formation of a protective oxide surface. Even then, nickel is reactive enough with oxygen that native nickel is rarely found on Earth’s surface, being mostly confined to the interiors of larger nickel–iron meteorites that were protected from oxidation during their time in space. On Earth, such native nickel is always found in combination with iron, a reflection of those elements’ origin as major end products of supernova nucleosynthesis. An iron–nickel mixture is thought to compose Earth’s inner core.
The use of nickel (as a natural meteoric nickel–iron alloy) has been traced as far back as 3500 BC. Nickel was first isolated and classified as a chemical element in 1751 by Axel Fredrik Cronstedt, who initially mistook its ore for a copper mineral. The element’s name comes from a mischievous sprite of German miner mythology, Nickel (similar to Old Nick), that personified the fact that copper-nickel ores resisted refinement into copper. An economically important source of nickel is the iron ore limonite, which often contains 1-2% nickel. Nickel’s other important ore minerals include garnierite, and pentlandite. Major production sites include the Sudbury region in Canada (which is thought to be of meteoric origin), New Caledonia in the Pacific, and Norilsk in Russia.
This is the VIRTUAL GEOSCIENCE WORKBENCH project (“vgw”)
This project was registered on SourceForge.net on Aug 21, 2008, and is described by the project team as follows:
The Virtual Geoscience Workbench for discontinuous systems is a computer software environment for modelling. We have made the combined Finite-Discrete Element Method (FEMDEM) the core of our solids technology.
Screenshots :
Download :
Source code for this project may be available as downloads or through one of the SCM repositories used by the project, as accessible from the project develop page.
A map of the River Niger, with national boundaries included
The Niger River is the principal river of western Africa, extending about 4,180 km (2,600 mi). Its drainage basin is 2,117,700 km2 (817,600 sq mi) in area. Its source is in the Guinea Highlands in southeastern Guinea. It runs in a crescent through Mali, Niger, on the border with Benin and then through Nigeria, discharging through a massive delta, known as the Niger Delta or the Oil Rivers, into the Gulf of Guinea in the Atlantic Ocean. The Niger is the third-longest river in Africa, exceeded only by the Nile and the Congo River (also known as the Zaïre River). Its main tributary is the Benue River.
The Niger is called Jeliba or Joliba “great river” in Manding; Orimiri or Orimili “great water” in Igbo; Egerew n-Igerewen “river of rivers” in Tuareg; Isa Ber “big river” in Songhay; Kwara in Hausa; and Oya in Yoruba. The origin of the name Niger, which originally applied only to the middle reaches of the river, is uncertain. The likeliest possibility is an alteration, by influence of Latin niger “black”, of the Tuareg name egerew n-igerewen, which is used along the middle reaches of the river around Timbuktu. As Timbuktu was the southern end of the principal Trans-Saharan trade route to the western Mediterranean, it was the source of most European knowledge of the region.
Medieval European maps applied the name Niger to the middle reaches of the river, in modern Mali, but Quorra (Kworra) to the lower reaches in modern Nigeria, as these were not recognized as being the same river. When European colonial powers began to send ships along the West coast of Africa in the 16th and 17th centuries, the Senegal River was often postulated to be seaward end of the Niger. The Niger Delta, pouring into the Atlantic through mangrove swamps and thousands of distributaries along more than a hundred miles, was thought to be no more than coastal wetlands. It was only with the 18th century visits of Mungo Park, who travelled down the Niger River and visited the great Sahelian empires of his day, that Europeans correctly identified the course of the Niger, and extending the name to its entire course.
The modern nations of Nigeria and Niger take their names from the river, marking contesting national claims by colonial powers of the “Upper”, “Lower” and “Middle” Niger river basin during the Scramble for Africa at the end of the 19th century.
Geography
The Niger River is a relatively “clear” river, carrying only a tenth as much sediment as the Nile because the Niger’s headwaters lie in ancient rocks that provide little silt. Like the Nile, the Niger floods yearly; this begins in September, peaks in November, and finishes by May.
An unusual feature of the river is the Inner Niger Delta, which forms where its gradient suddenly decreases. The result is a region of braided streams, marshes, and lakes the size of Belgium; the seasonal floods make the Delta extremely productive for both fishing and agriculture.
The river ‘loses’ nearly two-thirds of its potential flow in the Inner Delta between Ségou and Timbuktu to seepage and evaporation. All the water from the Bani River, which flows into the Delta at Mopti, does not compensate for the ‘losses’. The average ‘loss’ is estimated at 31 km3/year, but varies considerably between years. The river is then joined by various tributaries, but also loses more water to evaporation. The quantity of water entering Nigeria measured in Yola was estimated at 25 km3/year before the 1980s and at 13.5 km3/year during the 1980s. The most important tributary of the Niger in Nigeria is the Benue River which merges with the river at Lokoja in Nigeria. The total volume of tributaries in Nigeria is six times higher than the inflow into Nigeria, with a flow near the mouth of the river standing at 177.0 km3/year before the 1980s and 147.3 km3/year during the 1980s.
The above story is based on materials provided by Wikipedia
Chemical Formula: Na3Mg(CO3)2Cl Locality: Searles Lake, San Bernardino Co., California. Name Origin: Named after C. H. Northup (b.1861), grocer, of San Jose, California, who found the first specimen.
Northupite is an uncommon evaporite mineral, with the chemical formula Na3Mg(CO3)2Cl. It occurs as colourless to dark grey or brown octahedral crystals and as globular masses. In synthetic material it forms a series with tychite (Na6Mg2(CO3)4SO4).
It was discovered in 1895 at Searles Lake, San Bernardino County, California by C. H. Northup (born 1861) from San Jose, California, for whom Northupite is named.
It occurs associated with tychite, pirssonite at Searles Lake and with shortite, trona, pirssonite, gaylussite, labuntsovite, searlesite, norsethite, loughlinite, pyrite and quartz in the Green River Formation of Wyoming.
View looking north at the Ice River spring, the highest latitude perennial spring known. Located in the polar desert of northern Ellesmere Island, Nunavut, the high discharge spring carves a gully remarkable similar to those observed on Mars. Credit: Photo by Stephen Grasby
A Canadian team lead by Stephen Grasby reports the discovery of the highest latitude perennial spring known in the world. This high-volume spring demonstrates that deep groundwater circulation through the cryosphere occurs, and can form gullies in a region of extreme low temperatures and with morphology remarkably similar to those on Mars. The 2009 discovery raises many new questions because it remains uncertain how such a high-volume spring can originate in a polar desert environment.
Grasby and colleagues encountered the northernmost perennial spring in the world, which they have dubbed the Ice River Spring, on Ellesmere Island, Nunavut, Canadian High Arctic. The specific study area is north of Otto Fiord in a mountainous region underlain by carbonates of the Nansen Formation. The spring discharges at 300 m elevation from colluvium on a south-facing (21° incline) mountain slope. The unnamed mountain rises 800 m above sea level. Detailed recordings show that this spring flows year-round, even during 24 hours of darkness in the winter months, when air temperatures are as low as minus 50 degrees Celsius.
Detailed geochemistry shows that the waters originate from the surface and circulate down as deep as 3 km before returning through thick permafrost as a spring. This points to a much more active hydrogeological system in polar regions than previously thought possible, which is perhaps driven by glacial meltwater.
Another intriguing feature of the Ice River site is the remarkable similarity to mid-latitude gullies observed on Mars. The discovery of these features on Mars has led to suggestions that recent groundwater discharge has occurred from confined aquifers.
Note : The above story is based on materials provided by Geological Society of America.
Climate change is unlikely to lead to more days of extreme cold, similar to those that gripped the United States in a deep freeze last winter, new research has shown.
The Arctic amplification phenomenon refers to the faster rate of warming in the Arctic compared to places further south. It is this phenomenon that has been linked to a spike in the number of severe cold spells experienced in recent years over Europe and North America.
However, new research by University of Exeter expert Dr James Screen has shown that Arctic amplification has actually reduced the risk of cold extremes across large swathes of the Northern Hemisphere.
The intriguing new study, published in the scientific journal Nature Climate Change, questions growing fears that parts of Europe and North America will experience a greater number, or more severe, extreme cold days over the course of the next century.
Dr Screen, a Mathematics Research Fellow at the University of Exeter, said: “Autumn and winter days are becoming warmer on average, and less variable from day-to-day. Both factors reduce the chance of extremely cold days.”
The idea that there was a link between Arctic amplification and extreme weather conditions became prevalent during the severe winter weather that plagued large areas of the United States in January 2014, leading to major transport disruption, power cuts and crop damage.
In his study, Dr Screen examined detailed climate records to show that autumn and winter temperature variability has significantly decreased over the mid-to-high latitude Northern Hemisphere in recent decades.
He found that this has occurred mainly because northerly winds and associated cold days are warming more rapidly than southerly winds and warm days.
Dr Screen said: “Cold days tend to occur when the wind is blowing from the north, bringing Arctic air south into the mid-latitudes. Because the Arctic air is warming so rapidly these cold days are now less cold than they were in the past.”
Using the latest mathematical climate modelling, Dr Screen has also been able to show that these changes will continue in to the future, with projected future decreases in temperature variability in all seasons, except summer.
Note : The above story is based on materials provided by University of Exeter.
Chemical Formula: Mg3(SiO4)(F,OH)2 Locality: Ostanmosoa iron mine, Norberg, Vastmanland, Sweden. Name Origin: Named after its locality.
Norbergite is a nesosilicate mineral with formula Mg3(SiO4)(F,OH)2. It is a member of the humite group.
It was first described in 1926 for an occurrence in the Ostanmosoa iron mine in Norberg, Västmanland, Sweden, for which it is named. It occurs in contact metamorphic zones in carbonate rocks intruded by plutonic rocks or pegmatites supplying the fluorine. Associated minerals include dolomite, calcite, tremolite, grossular, wollastonite, forsterite, monticellite, cuspidine, fluoborite, ludwigite, fluorite and phlogopite.
Chinese and American scientists collaborating in the study of an active seismic fault that produced one of China’s most deadly earthquakes say their deployment of an airborne LiDAR system, which uses pulses of laser light to calculate distances and chart terrain features, has helped them produce the most precise topographical measurements ever of the fault zone.
“Light detection and ranging (LiDAR) presents a new approach to build detailed topographic maps effectively,” they report. They add that these high-precision three-dimensional models can be used to illustrate not only land surface changes following past quakes, but also features of past ruptures that could point to the possibility of future temblors.
Experts at the State Key Laboratory of Earthquake Dynamics and at the National Earthquake Infrastructure Service in Beijing, working with a colleague at the United States Geological Survey (USGS) in Pasadena, California, mounted a Leica ALS-60 LiDAR system aboard a Chinese Yun Five aircraft and then began scanning the Haiyuan fault zone in a series of flights over the course of a week. The fault zone is similar to the San Andreas fault in California, which has similarly been scanned and studied as a comparison.
“During the past century,” they explain in a new study, “the Haiyuan fault zone produced two great earthquakes: the M 8.5 Haiyuan earthquake in 1920, along the eastern Haiyuan fault, and the M 8–8.3 Gulang earthquake in 1927.”
“The Haiyuan earthquake of 16 December 1920 is one of the largest intra- continental earthquakes ever documented in history,” they add, “and ruptured about a 237-kilometer-long ground surface, with a maximum left-lateral slip of 10.2 m, and claimed over 220,000 lives.”
In the new study, “Quantitative study of tectonic geomorphology along the Haiyuan fault based on airborne LiDAR,” lead scientist Jing Liu and her colleagues at the Earthquake Dynamics Lab, part of the China Earthquake Administration in Beijing, state their experiments with the LiDAR scanning system and related building of a high-resolution topographical model provide “an example of how LiDAR data may be used to improve the study of active faults and the risk assessment of related hazards.”
Sections of the 3D digital model generated with the LiDAR data are “intensively analyzed to demonstrate tectonic geomorphic feature identification and displacement measurement,” they state. The LiDAR data are also used, for example, to calculate horizontal and vertical coseismic offsets in one section of the fault zone.
LiDAR data can be used to verify measurements made during fieldwork on offsets of tectonic landform features, state co-authors Tao Chen, Pei Zhen Zhang, Jing Liu, Chuan You Li, and Zhi Kun Ren, along with Ken Hudnut at the USGS, who visited the China Earthquake Administration to participate in this study. “The offset landforms are visualized on an office computer workstation easily, and specialized software may be used to obtain fault displacement measurements quantitatively,” they explain.
With LiDAR-generated digital models of the topography across fault zones, the “link between fault activity and large earthquakes is better recognized, as well as the potential risk for future earthquake hazards,” says the team of scientists.
More precise measurements of the active fault zone made possible by the LiDAR system, and their depiction in sophisticated three-dimensional maps, are helping scientists not only in basic research, but also in terms of calculating the probability of a seismic shock recurring, say the co-authors of the new study, which was published online in the journal Chinese Science Bulletin by Science China Press and Springer-Verlag.
Airborne laser swath mapping helps scientists to virtually remove the vegetation covering from topographical models; this “bare earth” representation provides for more accurate identification of tectonic features and changes following a quake.
A LiDAR airborne scanning system of the Earth’s terrain was deployed over the section of the southwestern Chinese province of Sichuan that was the epicenter of a Mw7.9 earthquake that struck in May of 2008; LiDAR data were used to map the scale of landslides and ultimately to develop rescue schemes.
In the new study, the Chinese and American scientists say that digital models created using LiDAR data from the Haiyuan fault zone “have a much higher resolution than existing topographic data and most aerial photographs, allowing us to map the locations of fault traces more accurately than ever.”
The high level of precision of the digital models constructed with information from the LiDAR laser scans of the topography in this fault zone will encourage future “site-specific fault activity studies,” state the scientists.
“In the future,” they predict, “we can expect that more and more concepts or models of fault activity would benefit from this unprecedented survey technique.”
Along the Haiyuan fault zone in the western Chinese province of Gansu, LiDAR scans and related digital models have already been used to identify 600 channels and other linear geomorphic features slated for more comprehensive analysis.
“The next step is to measure the displacements along the whole Haiyuan fault and analyze the principle of the slip distribution,” states the team of scientists, “which would help people better understand the fundamental link between fault activity and large earthquakes and assess potential risk for future earthquake hazards.”
In places where slip during past earthquakes was less pronounced, it is possible that future earthquakes could have greater slip in order to accommodate and equalize motions along the fault system. Alternatively, slip may be large repeatedly in some places and small elsewhere. Such variations in slip may help to assess future hazards, so observations of this kind are very important to answer unresolved questions that are central to research on hazards of earthquake fault zones around the world. More information:
Chinese Science Bulletin July 2014, Volume 59, Issue 20, pp 2396-2409. link.springer.com/article/10.1… %2Fs11434-014-0199-4
Note : The above story is based on materials provided by Science China Press
The Bain des Japonais Spring, an intertidal hydrothermal vent on Prony Bay. Note shimmering where fluids are mixing with seawater. Credit: Roy Price
Roy Price first heard about the hydrothermal vents in New Caledonia’s Bay of Prony a decade ago. Being a scuba diver and a geologist, he was fascinated by the pictures of a 38-meter-high calcite “chimney” that had precipitated out of the highly-alkaline vent fluid.
His attraction to this South Pacific site intensified over the years, as it was later revealed that the geochemistry of the hydrothermal fluids discharging in the Bay of Prony resemble that of the mid-Atlantic’s “Lost City,” one of the most spectacular of all hydrothermal vent systems. The unique chemical and biological conditions at the Lost City has led some scientists to speculate that the origin of life may have occurred around similar sorts of vents in the Earth’s distant past.
“The site in New Caledonia is very similar to the Lost City in many ways,” Price said.
Like the Lost City, the water that bubbles out of the Prony vents has an extremely alkaline pH of around 11. Temperatures reach up to 40° C (104° F) in some places, and fluids are highly enriched in dissolved hydrogen (H2) and methane (CH4). Calcium dissolved in the fluids reacts with bicarbonate in seawater, which leads to the formation of tall, monolithic calcite chimneys that look like ruins from an ancient civilization.
Besides having many geochemical similarities, Prony and the Lost City also have similar microbiology, as demonstrated by recent work from the “HYDROPRONY” research group, an interdisciplinary research team affiliated with the Mediterranean Institute of Oceanography (MIO) and the French Institute of Research for Development (IRD).
One big difference, however, is that the Lost City is nearly a kilometer underwater, whereas the main Prony chimney, called “the Needle of Prony” or “l’Aiguille” in French, nearly breaches the water surface, making the site accessible to divers.
Price, who is now a researcher at the School of Marine and Atmospheric Sciences, State University of New York, Stony Brook, asked the HYDROPRONY group for permission to join them on a field expedition in April 2014. His motivation was to test whether the Prony vents can produce organic compounds abiotically, without any biological influence.
“The abiotic production of hydrocarbons and other simple organic compounds in places such as these may have led or at least contributed to abiogenesis—the [long-ago] switch from abiotic chemical reactions to biologically-mediated reactions probably similar to today’s microbial metabolisms,” Price said.
With funding from a NASA Early Career Collaboration award, Price flew to New Caledonia to test whether the chemical precursors of this ancient switch can be found in Prony Bay.
As soon as he arrived on New Caledonia, Price was struck by the red soil that covers the southern part of the main island. This soil comes from the erosion of ultramafic rock, which is a rare type of iron-rich, silica-poor rock, only found in a few places on earth today.
Ultramafic rocks give rise to the hydrothermal vents in both Prony Bay and the Lost City. When exposed to water, ultramafic rocks go through a chemical weathering process called serpentinization. Specifically, the iron in the rock oxidizes, producing hydrogen gas (H2), as well as heat. The hydrogen reacts with carbon dioxide in the water to produce one of the simplest organic molecules, methane (CH4).
“This is a key point—an organic compound produced without any biological interactions whatsoever,” Price explained. “Other slightly more complex organic molecules can also be produced abiotically.”
Ultramafic rocks are not very common on the Earth’s surface now, so it’s rare to find areas with ongoing serpentinization. But billions of years ago when life was getting its start, “ultramafic rocks may have been much more abundant,” Price said. The Earth was much hotter back then, allowing more iron-rich (ultramafic-producing) lava to flow up from the mantle to the crust.
One might imagine, then, that the first precursors to life took advantage of the conditions around these types of hydrothermal vents, co-opting the geochemical reactions to form their own “biological serpentinization” that extracted energy from the reduction of carbon dioxide with hydrogen, forming methane in the process.
Price’s experiments in New Caledonia could provide some ground truth for these origin-of-life speculations. The methane and hydrogen in the hydrothermal fluids from Prony will be analyzed in the lab to determine their carbon and hydrogen isotopic abundances. If the vent’s methane is enriched in carbon-13 and depleted in deuterium (heavy hydrogen), that could be evidence of abiotic production.
“If the methane is produced abiotically, then we will have in the Prony hydrothermal site an early Earth analog which may help us understand the complex sequence of events which led to the origin of life,” Price said.
Fielding an answer
In the days leading up to his first dive, Price spoke with several IRD researchers, including Bernard Pelletier and Claude Payri, the investigators who recently ‘rediscovered’ the hydrothermal cones in the Bay of Prony.
On April 16, Price met the diving leader, Eric Folcher of IRD, who drove him out to the boat launch on the bay. They were joined in the field by two members of the HYDROPRONY group—microbiologists Gaël Erauso of the Mediterranean Institute of Oceanography (University of Marseille) and Mylène Hugoni of the University Blaise Pascal. They are studying the genetic make-up of the microbes and viruses that inhabit the vent environments.
“The weather was particularly good this day, lacking the nearly constant wind the island experiences,” Price recounted. “This not only meant a very smooth ride out to the Needle, but also hinted that there would be very good visibility during the dive.”
When the team’s boat pulled into position, Price caught his first glimpse of the Needle, with its mineral-crusted dome clearly visible about 3 meters below the surface.
Price prepared his sampling equipment, which included several gas-tight syringes to syphon fluids discharging from the vents. When he and Folcher dived in the water, they were immediately surprised by a swarm of moon jellyfish.
“Within my field of view at the surface, I could see dozens of these stinging medusa,” Price said.
The top of the Needle has no active venting, so the divers swam down the side of the chimney to a depth of about 12 meters (39 feet), where they began to see white-tipped, cone-like structures out of which hydrothermal fluids flow.
The water coming out of the vents is fresh, not salty, causing it to shimmer when it mixes with the surrounding seawater. The vent fluid is fresh because it originates from rainwater, which percolates down through the rocks on the island. This water then reacts with the rocks by the serpentinization reactions described earlier, and finally drains down beneath the bay before discharging at the Needle and other areas in and around the bay.
This freshwater distinguishes the Prony hydrothermal field from other sites such as Lost City, which are fed with saltwater. Another unique feature of Prony is that it is in the photic zone, where sunlight can reach the microbial communities, as it does in terrestrial hot springs.
“All this suggests that Prony is a hybrid vent system, with geochemical and microbial characteristics similar to both terrestrial and marine systems,” Price said.
The divers approached a striking cone-like structure at approximately 16 meters (52 feet) deep to obtain samples. A temperature reading showed that the exiting fluids were about 33° C (91° F), which is 8 to 9°C higher than the ambient seawater. The fluids are heated by the serpentinization process, rather than the volcanic processes that power other vents.
The venting is very slow, so it took Price about 10 minutes to fill just one of his 50-milliliter syringes with vent fluid while preventing seawater from being sucked in as well. Maintaining position in the water during this filling procedure was one of the main challenges on this diving expedition.
“We cannot touch the cone, for fear of breaking it or crushing some of the reef organisms,” he said. “For a scuba diver, having the ability to hang in the water column like this takes a lot of practice, and it is not so easy. I use my breathing to maintain my position. If I’m dropping a little too low, I’ll take a slightly deeper breath. The air in my lungs then raises me a little. Too much and I breath out, which drops me back into position.”
With an hour of dive time, Price managed to collect five syringes of hydrothermal fluids. Back on the boat, he “fixed” the samples so that their geochemical properties wouldn’t begin evolving inside the sample tubes. He measured a pH of 10.1 in the samples, which is one of the highest values obtained for these submarine vents. Full analysis will occur later in the lab.
Spring loading
In addition to the syringe samples, the researchers also needed to collect larger volume samples in order to ‘capture’ organisms living in this unique environment. Erauso and Hugoni plan to do a thorough DNA survey in order to catalogue the diversity of species, and perhaps cultivate unidentified microorganisms, including Archaea, who thrive in these very alkaline environments.
For this biological research, the team collected mineral precipitates, where these vent organisms might be living. Underwater, the divers also installed a funnel above one vent in order to concentrate the discharge into a large plastic bag. The goal was to collect around 40 liters of fluid, which could then be filtered to remove microbes and viruses. However, the low flow rate posed a problem in filling the large bags.
The team had better luck at two nearby hot springs, the Bain des Japonais Spring and the Rivière des Kaoris Spring. Both of these sites are intertidal, located right on the coast of the Bay of Prony, where they get covered by seawater in high tide.
The Japonais site consists of a handful of outcroppings, which are shorter versions of the chimneys found in the middle of bay. At low tide, hydrothermal fluid discharges from the depths without much mixing with seawater. The team found that this ‘pristine’ fluid had a temperature 41° C (106° F) and a pH of 11.2, giving some indication of the geochemical characteristics of the subsurface fluids.
The Kaoris Spring is at the mouth of a stream that empties into Prony Bay. It consists of a large terrace, where warm hydrothermal fluid helps to support a variety of microbial biofilms. The researchers collected 40 liters of the fluids along with some slices of these biofilms.
Primordial soup kitchens
The samples from the Needle and the two intertidal hot springs are currently being analyzed, and Price plans to use the results in an upcoming NASA Exobiology proposal, which aims to give the first detailed carbon cycling geochemistry from the Prony hydrothermal field.
“The more I think about it, the more I wonder about systems like this on the early Earth,” Price said. “Today, groundwater that reacts with underlying rocks can be seen discharging along the coastlines everywhere around the world. This phenomenon must have occurred on the early Earth, but [back then] many of the rocks would have been ultramafic.”
Hybrid, Prony-like systems may therefore have been very common during our planet’s beginnings, Price said. They may also have existed on Mars and other planetary bodies in our solar system.
“Based on our current understanding of the early Earth, these types of transitional environments could have been highly important for origin of life scenarios,” Price said.
Note : The above story is based on materials provided by Astrobio.net
Chemical Formula: (Ni,Co)As3-x Locality: Schneeberg, Saxony, Germany. Name Origin: Named as the nickel-rich version of skutterudite.
Skutterudite is a cobalt arsenide mineral that has variable amounts of nickel and iron substituting for cobalt with a general formula: (Co,Ni,Fe)As3. Some references give the arsenic a variable formula subscript of 2-3. High nickel varieties are referred to as nickel-skutterudite, previously chloanthite. It is a hydrothermal ore mineral found in moderate to high temperature veins with other Ni-Co minerals. Associated minerals are arsenopyrite, native silver, erythrite, annabergite, nickeline, cobaltite, silver sulfosalts, native bismuth, calcite, siderite, barite and quartz. It is mined as an ore of cobalt and nickel with a by-product of arsenic.
The crystal structure of this mineral has been found to have important technological uses for several compounds isostructural with the mineral.
The mineral has a bright metallic luster, and is tin white or light steel gray in color with a black streak. The specific gravity is 6.5 and the hardness is 5.5-6. Its crystal structure is isometric with cube and octahedron forms similar to that of pyrite. The arsenic content gives a garlic odor when heated or crushed.
It was discovered in Skuterud Mines, Modum, Buskerud, Norway, in 1845. Smaltite is a synonym for the mineral. Notable occurrences include Cobalt, Ontario, Skuterud, Norway, and Franklin, New Jersey in the United States. The rare arsenide minerals are classified in Dana’s sulfide mineral group, even though it contains no sulfur.
The dinosaur named ”Sue,” a 41-foot-long Tyrannosaurus rex, is shown on display at the Field Museum in Chicago, Illinois in this May 17, 2000 file photo. Credit: Reuters/Sue Ogrocki/Files
The hot question of whether dinosaurs were warm-blooded like birds and mammals or cold blooded like reptiles, fish and amphibians finally has a good answer.
Dinosaurs, for eons Earth’s dominant land animals until being wiped out by an asteroid 65 million years ago, were in fact somewhere in between.
Scientists said on Thursday they evaluated the metabolism of numerous dinosaurs using a formula based on their body mass as revealed by the bulk of their thigh bones and their growth rates as shown by growth rings in fossil bones akin to those in trees.
The study, published in the journal Science, assessed 21 species of dinosaurs including super predators Tyrannosaurus and Allosaurus, long-necked Apatosaurus, duckbilled Tenontosaurus and bird-like Troodon as well as a range of mammals, birds, bony fish, sharks, lizards, snakes and crocodiles.
“Our results showed that dinosaurs had growth and metabolic rates that were actually not characteristic of warm-blooded or even cold-blooded organisms. They did not act like mammals or birds nor did they act like reptiles or fish,” said University of Arizona evolutionary biologist and ecologist Brian Enquist.
“Instead, they had growth rates and metabolisms intermediate to warm-blooded and cold-blooded organisms of today. In short, they had physiologies that are not common in today’s world.”
There has been a long-standing debate about whether dinosaurs were slow, lumbering cold-blooded animals – as scientists first proposed in the 19th century – or had a uniquely advanced, more warm-blooded physiology.
As scientists unearthed remains of more and more fast-looking dinosaurs like Velociraptor, some championed the idea dinosaurs were as active and warm–blooded as mammals and birds. The realization that birds arose from small feathered dinosaurs seemed to support that view.
University of New Mexico biologist John Grady said the idea that creatures must be either warm-blooded or cold-blooded is too simplistic when looking over the vast expanse of time. Like dinosaurs, some animals alive today like the great white shark, leatherback sea turtle and tuna do not fit easily into either category, Grady added.
“A better answer would be ‘in the middle.’ By examining animal growth and rates of energy use, we were able to reconstruct a metabolic continuum, and place dinosaurs along that continuum. Somewhat surprisingly, dinosaurs fell right in the middle,” Grady said.
The researchers called creatures with this medium-powered metabolism mesotherms, as contrasted to ectotherms (cold–blooded animals with low metabolic rates that do not produce much heat and bask in the sun to warm up) and endotherms (warm–blooded animals that use heat from metabolic reactions to maintain a high, stable body temperature).
Grady said an intermediate metabolism may have allowed dinosaurs to get much bigger than any mammal ever could. Warm–blooded animals need to eat a lot so they are frequently hunting or munching on plants. “It is doubtful that a lion the size of T. rex could eat enough to survive,” Grady said.
Note : The above story is based on materials provided by Will Dunham; Editing by Marguerita Choy “Reuters”
A group of men attending a bachelor party stumbled across a rare fossil of a mastodon skull, complete with its tusks, in sand at a lakeshore in a New Mexico state park, a museum spokesman said on Thursday.
Randall Gann of the New Mexico Museum of Natural History and Science said the partygoers discovered the fossil earlier this week in Elephant Butte State Park, an area of arid hills surrounding a reservoir about 155 miles (250 km) south of Albuquerque.
He said the museum’s head paleontologist was amazed by the find, calling it “the most complete mastodon skull with attached tusks he has seen in 20 years.”
Mastodons were Ice Age relatives of the elephant that stood 10 feet (3 meters) tall and migrated to North America some 15 million years ago. They ranged across the continent with saber tooth tigers, giant sloths and American camels, before becoming extinct about 10,000 years ago.
The revelers who made the discovery first contacted a professor at the University of New Mexico, who then put them in touch with the museum’s head paleontologist Gary Morgan.
Gann said scientists from the museum planned to act quickly.
“Because it is in sand and not buried in rock, Dr. Morgan feels he can excavate the skull, cast it, and remove it today,” the spokesman said.Shannon Parill, an employee of Elephant Butte State Park, said it was surprising the fossil was found in such a popular area, which attracts thousands of outdoor enthusiasts every year with its boating, hiking, fishing and camping opportunities.
Beth Wojahn, spokeswoman for New Mexico’s Energy, Minerals and Natural Resources Department, praised the group involved.
“What is noteworthy is the men who found the skull did not disturb it and called the right people,” Wojahn said.
Note : The above story is based on materials provided by Daniel Wallis and Will Dunham ” Reuters “
Chemical Formula: Mg(HPO4)·3H2O Locality: Skipton lava tube caves, 40 km southwest of Ballarat, Victoria, Australia. Name Origin: Named for James Cosmo Newbery (1843-1895), geologist, Melbourne, Australia, who initially found the mineral.
Metasprigina fossil from Marble Canyon, which lived about 514 to 505 million years ago during the Cambrian period is shown in this handout image. Credit: Reuters/Jean-Bernard Caron/ROM/Handout via Reuters
This is certainly not just another fish tale.
A tiny jawless fish that lived more than half a billion years ago is providing scientists with a treasure trove of information about the very dawn of vertebrate life on Earth.
Researchers on Wednesday described about 100 fossil specimens of the fish unearthed at the Burgess Shale site in the Canadian Rockies and other locales, many exquisitely preserved showing the primitive body structures that would later evolve into jaws.
The fish, Metaspriggina, lived about 515 to 500 million years ago amid the astonishing flourishing of complex life during the Cambrian Period. While two fragmentary specimens had been found previously, the new ones revealed unprecedented detail about one of the earliest known vertebrates.
Creatures like Metaspriggina began the lineage of vertebrates – animals with backbones – that later would include the whole range of jawed fishes, amphibians, reptiles, birds and mammals including people.
“It allows an understanding of where we come from and what our most distant relatives might have looked like,” said Jean-Bernard Caron, a paleontologist at the Royal Ontario Museum in Toronto. “Because of its great age – more than half a billion year old – Metaspriggina provides a deep down view at the origins of the vertebrates.”
Metaspriggina was a soft-bodied jawless fish no bigger than a person’s thumb – about 2-1/2 inches (6 cm) long, with a small head, a narrow, tapering body, a pair of large eyes atop the head and a pair of small nasal sacs.
It did not have bones but possessed a skull possibly made of cartilage as well as precursors to vertebrae and a skeletal rod called a “notochord” that provided body support like backbones would do in later vertebrates. It is unclear if it had fins.
The scientists were especially excited about the gill structure of the fish because of the preview it gives to the anatomy of later vertebrates – paving the way for the jaws that would open a world of possibilities for so many later creatures.
Metaspriggina boasted seven pairs of rod-like structures called gill arches, or branchial arches, that functioned for both filtration of food particles and respiration. The first pair of these gill arches was more robust than the others and presaged the first step in the evolution of jaws, Caron said.
Scientists have known about the importance of these arches in the evolution of vertebrates but had never before been able to see such an early example.
“Metaspriggina is important because it both fills an important gap in our understanding of the early evolution of the group to which we belong, but in particular shows with remarkable clarity the arrangement of the so-called branchial arches,” University of Cambridge paleontologist Simon Conway Morris said.
Part of the jaw bones eventually evolved into tiny middle ear bones in mammals, Caron added, noting that the evolution of these arches “had a profound impact on how vertebrates look, live and function today.”
The study was published in the journal Nature.
Note : The above story is based on materials provided by Will Dunham; Editing by Tom Brown ” Reuters”
Three-quarters of the Earth’s water may be locked deep underground in a layer of rock, scientists say. Photograph: Blue Line Pictures/Getty Images
After decades of searching scientists have discovered that a vast reservoir of water, enough to fill the Earth’s oceans three times over, may be trapped hundreds of miles beneath the surface, potentially transforming our understanding of how the planet was formed.
The water is locked up in a mineral called ringwoodite about 660km (400 miles) beneath the crust of the Earth, researchers say. Geophysicist Steve Jacobsen from Northwestern University in the US co-authored the study published in the journal Science and said the discovery suggested Earth’s water may have come from within, driven to the surface by geological activity, rather than being deposited by icy comets hitting the forming planet as held by the prevailing theories.
“Geological processes on the Earth’s surface, such as earthquakes or erupting volcanoes, are an expression of what is going on inside the Earth, out of our sight,” Jacobsen said.
“I think we are finally seeing evidence for a whole-Earth water cycle, which may help explain the vast amount of liquid water on the surface of our habitable planet. Scientists have been looking for this missing deep water for decades.”
Jacobsen and his colleagues are the first to provide direct evidence that there may be water in an area of the Earth’s mantle known as the transition zone. They based their findings on a study of a vast underground region extending across most of the interior of the US.
Ringwoodite acts like a sponge due to a crystal structure that makes it attract hydrogen and trap water.
If just 1% of the weight of mantle rock located in the transition zone was water it would be equivalent to nearly three times the amount of water in our oceans, Jacobsen said.
The study used data from the USArray, a network of seismometers across the US that measure the vibrations of earthquakes, combined with Jacobsen’s lab experiments on rocks simulating the high pressures found more than 600km underground.
It produced evidence that melting and movement of rock in the transition zone – hundreds of kilometres down, between the upper and lower mantles – led to a process where water could become fused and trapped in the rock.
The discovery is remarkable because most melting in the mantle was previously thought to occur at a much shallower distance, about 80km below the Earth’s surface.
Jacobsen told the New Scientist that the hidden water might also act as a buffer for the oceans on the surface, explaining why they have stayed the same size for millions of years. “If [the stored water] wasn’t there, it would be on the surface of the Earth, and mountaintops would be the only land poking out,” he said.
Note : The above story is based on materials provided by Melissa Davey For The Guardian
