Feb 15, 2016 09:11 AM
(This post was last modified: Feb 15, 2016 09:11 AM by C C.)
Drones give scientists a new self-service approach
https://www.sciencedaily.com/releases/20...141747.htm
RELEASE: Earth and environmental scientists have often had to rely on piloted aircraft and satellites to collect remote sensing data, platforms that have traditionally been controlled by large research organizations or regulatory agencies.
Thanks to the increased affordability and dramatic technological advances of drones, or Unmanned Aerial Vehicles (UAVs), however, earth and environmental scientists can now conduct their own long-term high-resolution experiments at a fraction of the cost of using aircraft or satellites.
"UAVs are poised to revolutionize remote sensing in the earth and environmental sciences," says Enrique Vivoni, hydrologist and professor at Arizona State University's School of Earth and Space Exploration and Ira A. Fulton Schools of Engineering. "They let individual scientists obtain low-cost repeat imagery at high resolution and tailored to a research team's specific interest area."
Vivoni's own research has focused on rangeland locations in the Sonoran and Chihuahuan deserts, which cover large expanses of northern Mexico and the U.S. Southwest. Using UAVs in these areas has allowed for improved studies on land-atmosphere exchanges and vegetation-runoff interactions.
Once used exclusively for military application, UAV's now offer many civilian uses. Their advances in flight control, robotics and miniaturized sensors, are providing an unprecedented opportunity for high-resolution data collection.
"The biggest challenge for earth and environmental scientists has been obtaining high-resolution [data for] characterizations and predictions," says Vivoni.
Both fixed wing and rotary wing UAVs can be used for ecohydrologic investigations, according to Vivoni. Researchers can also use quad-copters with photo cameras or video cameras, such as the Phantom series.
Vivoni will give his talk "Ecohydrology with Unmanned Aerial Vehicles" on February 13 at the American Association for the Advancement of Science (AAAS) 2016 Annual Meeting in Washington, D.C.
The presentation summarizes his work with associate professor Srikanth Saripalli of the School of Earth and Space Exploration, graduate students Nicole Pierini, Cody Anderson and Adam Schreiner-McGraw as well as collaborators from the Agriculture Research Service of the U.S. Department of Agriculture Jornada Experimental Range.
"We believe unmanned aerial vehicles can fundamentally change how ecological and hydrological science is conducted and offer ways to merge remote sensing, environmental sensor networks and numerical models," Vivoni says.
Discovery of new iron oxides points to large oxygen source inside Earth: High-pressure experiments reveal chemical complexity of iron oxides
https://www.sciencedaily.com/releases/20...141747.htm
RELEASE: Using a special high-pressure chamber, scientists have discovered two new iron oxides in experiments at DESY's X-ray light source PETRA III and other facilities. The discovery points to a huge, hitherto unknown oxygen source in the lower mantle of Earth. The team led by Dr. Elena Bykova from the University of Bayreuth reports its results in the scientific journal Nature Communications.
Iron oxides in nature take on different forms. "The most common iron oxide is hematite, Fe2O3, which is the end product of many geological processes and the main source of iron for our civilization," explains Bykova. During the past five years, however, scientists have discovered other iron oxides like Fe4O5, Fe5O6, and Fe13O19 that form at high pressures and temperatures. Investigating the behaviour of hematite and magnetite (Fe3O4) further, Bykova and her colleagues used a special pressure chamber at DESY's measuring station for extreme conditions P02.2.
"In this so-called diamond anvil cell, a minute sample can be compressed between two diamonds to several hundred thousand times the atmospheric pressure while a meticulously aligned laser can also heat the sample through the transparent diamond anvils to several thousand degrees Celsius," explains DESY scientist Dr. Hanns-Peter Liermann, head of the measuring station and a co-author of the paper. At the same time, the exceptionally bright and small X-ray beam of PETRA III can track structural changes in the sample. Similar measurements were also made at the European Synchrotron Radiation Source ESRF in France and at the Advanced Photon Source APS in the US.
When the scientists applied a pressure of more than 67 gigapascals (about 670,000 times the standard atmospheric pressure) to their hematite samples and heated it to more than 2400 degrees Celsius, Fe2O3 decomposed and formed Fe5O7, an iron oxide that has not been seen before. These conditions correspond to roughly 1500 kilometres below the surface of Earth. At an even higher pressure of 70 gigapascals, corresponding to about 1670 kilometres below the surface, magnetite decomposed and another new iron oxide formed, Fe25O32. The formation of both so far unknown compounds leads to the release of oxygen.
Although iron oxides do not normally exist in the bulk of Earth' lower mantle, they can be transported there via subduction zones, where one tectonic plate dives under another. Hematite and magnetite are major components of so-called Banded Iron Formations (BIFs) and ironstones, huge sedimentary rock formations occurring on all continents. These formations may reach up to several hundred meters in thickness and hundreds of kilometres in length.Deposited in the world's oceans about two billions years ago, Banded Iron Formations form part of the ocean floor and are recycled into Earth's interior by subduction to great depths, possibly extending to the core-mantle boundary region.
As the team now observed, at conditions corresponding to the middle of Earth's lower mantle hematite and magnetite decompose releasing huge amounts of oxygen-rich fluid (as oxygen is usually liquid under these conditions). "We estimate that this source so far provided an amount of oxygen equivalent to eight to ten times the mass of oxygen in the atmosphere," says Bykova. "That's a surprise, and it is not quite clear what happens with the oxygen down there."
The oxygen-rich fluid could either locally oxidize surrounding materials or pass to the transition zone, or even to the upper mantle. "This remains to be explored," says co-author Dr. Maxim Bykov of the University of Bayreuth. "For now, we can only say that there is a huge source of oxygen in the mantle that can significantly affect geochemical processes by changing oxidation states and mobilizing trace elements. This will open a large new field of modelling."
The discovery of the new iron oxides thus not only adds to the knowledge about fundamental characteristics of these substances, underlines Bykov. "Our work shows that we maybe miss significant parts of the processes in Earth. Subducted slabs can apparently produce unexpected things. The effects on Earth's global dynamics, including climate variations, have to be investigated."
Deutsches Elektronen-Synchrotron DESY is the leading German accelerator centre and one of the leading in the world. DESY is a member of the Helmholtz Association and receives its funding from the German Federal Ministry of Education and Research (BMBF) (90 per cent) and the German federal states of Hamburg and Brandenburg (10 per cent). At its locations in Hamburg and Zeuthen near Berlin, DESY develops, builds and operates large particle accelerators, and uses them to investigate the structure of matter. DESY's combination of photon science and particle physics is unique in Europe.
https://www.sciencedaily.com/releases/20...141747.htm
RELEASE: Earth and environmental scientists have often had to rely on piloted aircraft and satellites to collect remote sensing data, platforms that have traditionally been controlled by large research organizations or regulatory agencies.
Thanks to the increased affordability and dramatic technological advances of drones, or Unmanned Aerial Vehicles (UAVs), however, earth and environmental scientists can now conduct their own long-term high-resolution experiments at a fraction of the cost of using aircraft or satellites.
"UAVs are poised to revolutionize remote sensing in the earth and environmental sciences," says Enrique Vivoni, hydrologist and professor at Arizona State University's School of Earth and Space Exploration and Ira A. Fulton Schools of Engineering. "They let individual scientists obtain low-cost repeat imagery at high resolution and tailored to a research team's specific interest area."
Vivoni's own research has focused on rangeland locations in the Sonoran and Chihuahuan deserts, which cover large expanses of northern Mexico and the U.S. Southwest. Using UAVs in these areas has allowed for improved studies on land-atmosphere exchanges and vegetation-runoff interactions.
Once used exclusively for military application, UAV's now offer many civilian uses. Their advances in flight control, robotics and miniaturized sensors, are providing an unprecedented opportunity for high-resolution data collection.
"The biggest challenge for earth and environmental scientists has been obtaining high-resolution [data for] characterizations and predictions," says Vivoni.
Both fixed wing and rotary wing UAVs can be used for ecohydrologic investigations, according to Vivoni. Researchers can also use quad-copters with photo cameras or video cameras, such as the Phantom series.
Vivoni will give his talk "Ecohydrology with Unmanned Aerial Vehicles" on February 13 at the American Association for the Advancement of Science (AAAS) 2016 Annual Meeting in Washington, D.C.
The presentation summarizes his work with associate professor Srikanth Saripalli of the School of Earth and Space Exploration, graduate students Nicole Pierini, Cody Anderson and Adam Schreiner-McGraw as well as collaborators from the Agriculture Research Service of the U.S. Department of Agriculture Jornada Experimental Range.
"We believe unmanned aerial vehicles can fundamentally change how ecological and hydrological science is conducted and offer ways to merge remote sensing, environmental sensor networks and numerical models," Vivoni says.
Discovery of new iron oxides points to large oxygen source inside Earth: High-pressure experiments reveal chemical complexity of iron oxides
https://www.sciencedaily.com/releases/20...141747.htm
RELEASE: Using a special high-pressure chamber, scientists have discovered two new iron oxides in experiments at DESY's X-ray light source PETRA III and other facilities. The discovery points to a huge, hitherto unknown oxygen source in the lower mantle of Earth. The team led by Dr. Elena Bykova from the University of Bayreuth reports its results in the scientific journal Nature Communications.
Iron oxides in nature take on different forms. "The most common iron oxide is hematite, Fe2O3, which is the end product of many geological processes and the main source of iron for our civilization," explains Bykova. During the past five years, however, scientists have discovered other iron oxides like Fe4O5, Fe5O6, and Fe13O19 that form at high pressures and temperatures. Investigating the behaviour of hematite and magnetite (Fe3O4) further, Bykova and her colleagues used a special pressure chamber at DESY's measuring station for extreme conditions P02.2.
"In this so-called diamond anvil cell, a minute sample can be compressed between two diamonds to several hundred thousand times the atmospheric pressure while a meticulously aligned laser can also heat the sample through the transparent diamond anvils to several thousand degrees Celsius," explains DESY scientist Dr. Hanns-Peter Liermann, head of the measuring station and a co-author of the paper. At the same time, the exceptionally bright and small X-ray beam of PETRA III can track structural changes in the sample. Similar measurements were also made at the European Synchrotron Radiation Source ESRF in France and at the Advanced Photon Source APS in the US.
When the scientists applied a pressure of more than 67 gigapascals (about 670,000 times the standard atmospheric pressure) to their hematite samples and heated it to more than 2400 degrees Celsius, Fe2O3 decomposed and formed Fe5O7, an iron oxide that has not been seen before. These conditions correspond to roughly 1500 kilometres below the surface of Earth. At an even higher pressure of 70 gigapascals, corresponding to about 1670 kilometres below the surface, magnetite decomposed and another new iron oxide formed, Fe25O32. The formation of both so far unknown compounds leads to the release of oxygen.
Although iron oxides do not normally exist in the bulk of Earth' lower mantle, they can be transported there via subduction zones, where one tectonic plate dives under another. Hematite and magnetite are major components of so-called Banded Iron Formations (BIFs) and ironstones, huge sedimentary rock formations occurring on all continents. These formations may reach up to several hundred meters in thickness and hundreds of kilometres in length.Deposited in the world's oceans about two billions years ago, Banded Iron Formations form part of the ocean floor and are recycled into Earth's interior by subduction to great depths, possibly extending to the core-mantle boundary region.
As the team now observed, at conditions corresponding to the middle of Earth's lower mantle hematite and magnetite decompose releasing huge amounts of oxygen-rich fluid (as oxygen is usually liquid under these conditions). "We estimate that this source so far provided an amount of oxygen equivalent to eight to ten times the mass of oxygen in the atmosphere," says Bykova. "That's a surprise, and it is not quite clear what happens with the oxygen down there."
The oxygen-rich fluid could either locally oxidize surrounding materials or pass to the transition zone, or even to the upper mantle. "This remains to be explored," says co-author Dr. Maxim Bykov of the University of Bayreuth. "For now, we can only say that there is a huge source of oxygen in the mantle that can significantly affect geochemical processes by changing oxidation states and mobilizing trace elements. This will open a large new field of modelling."
The discovery of the new iron oxides thus not only adds to the knowledge about fundamental characteristics of these substances, underlines Bykov. "Our work shows that we maybe miss significant parts of the processes in Earth. Subducted slabs can apparently produce unexpected things. The effects on Earth's global dynamics, including climate variations, have to be investigated."
Deutsches Elektronen-Synchrotron DESY is the leading German accelerator centre and one of the leading in the world. DESY is a member of the Helmholtz Association and receives its funding from the German Federal Ministry of Education and Research (BMBF) (90 per cent) and the German federal states of Hamburg and Brandenburg (10 per cent). At its locations in Hamburg and Zeuthen near Berlin, DESY develops, builds and operates large particle accelerators, and uses them to investigate the structure of matter. DESY's combination of photon science and particle physics is unique in Europe.