New report details more geoscience job opportunities than students

This image graphs industries hiring geoscience degree graduates by bachelors, masters and doctoral degree brackets. -  Carolyn Wilson: cwilson@americangeosciences.org
This image graphs industries hiring geoscience degree graduates by bachelors, masters and doctoral degree brackets. – Carolyn Wilson: cwilson@americangeosciences.org

In the American Geosciences Institute’s newest Status of the Geoscience Workforce Report, released May 2014, jobs requiring training in the geosciences continue to be lucrative and in-demand. Even with increased enrollment and graduation from geoscience programs, the data still project a shortage of around 135,000 geoscientists needed in the workforce by the end of the decade.

“Industry has recognized, and is mitigating the upcoming shortage of skilled geoscientists in their employ, but the federal geoscience workforce is still demonstrably shrinking” report author Carolyn Wilson said, noting that the federal geoscience workforce decreased in all sectors except meteorology; this includes geoscientists skilled in the energy, mining/minerals and hydrology fields. Combined with continued unevenness is the workforce readiness of many geoscience graduates and a regionally hot job market, the geosciences are a dynamic component of the U.S. economy.

Employers have appreciably skilled geoscientists to choose from too. Numbers of graduating geoscience majors who started their degrees at a two-year colleges have increased, as have the number of students participating in a field camp experiences-an important facet of a geoscience degree, where students get experience interpreting the landforms critical to determining where energy or water resources exist, as well as interpreting locations susceptible to hazards like flooding or landslides. Most students graduating from a geoscience degree program have taken math courses up to a calculus-II level, but there is still concern from employers over whether these students are graduating with enough quantitative experience to be completely apt for a career in the geosciences.

Employers underscore the necessity of having enough skilled grads to meet vacancies that will exist in the geoscience sector in the upcoming decades.

“It’s important that working knowledge is passed down because losing the institutional knowledge could have negative impacts for the overall productivity of these companies.” Wilson said.

“Most importantly there is incredible potential for institutions to recruit from the diverse talent pools arising at two year institutions, and many career opportunities available to students enrolled in geoscience programs, and early-career geoscientists entering the workforce,” Wilson said. “Plus, this is the first time we have seen a major shift in employment patterns in over a generation, with increasing number of bachelor recipients securing geoscience positions, and newly minted Master’s finding themselves in high demand.”

New report details more geoscience job opportunities than students

This image graphs industries hiring geoscience degree graduates by bachelors, masters and doctoral degree brackets. -  Carolyn Wilson: cwilson@americangeosciences.org
This image graphs industries hiring geoscience degree graduates by bachelors, masters and doctoral degree brackets. – Carolyn Wilson: cwilson@americangeosciences.org

In the American Geosciences Institute’s newest Status of the Geoscience Workforce Report, released May 2014, jobs requiring training in the geosciences continue to be lucrative and in-demand. Even with increased enrollment and graduation from geoscience programs, the data still project a shortage of around 135,000 geoscientists needed in the workforce by the end of the decade.

“Industry has recognized, and is mitigating the upcoming shortage of skilled geoscientists in their employ, but the federal geoscience workforce is still demonstrably shrinking” report author Carolyn Wilson said, noting that the federal geoscience workforce decreased in all sectors except meteorology; this includes geoscientists skilled in the energy, mining/minerals and hydrology fields. Combined with continued unevenness is the workforce readiness of many geoscience graduates and a regionally hot job market, the geosciences are a dynamic component of the U.S. economy.

Employers have appreciably skilled geoscientists to choose from too. Numbers of graduating geoscience majors who started their degrees at a two-year colleges have increased, as have the number of students participating in a field camp experiences-an important facet of a geoscience degree, where students get experience interpreting the landforms critical to determining where energy or water resources exist, as well as interpreting locations susceptible to hazards like flooding or landslides. Most students graduating from a geoscience degree program have taken math courses up to a calculus-II level, but there is still concern from employers over whether these students are graduating with enough quantitative experience to be completely apt for a career in the geosciences.

Employers underscore the necessity of having enough skilled grads to meet vacancies that will exist in the geoscience sector in the upcoming decades.

“It’s important that working knowledge is passed down because losing the institutional knowledge could have negative impacts for the overall productivity of these companies.” Wilson said.

“Most importantly there is incredible potential for institutions to recruit from the diverse talent pools arising at two year institutions, and many career opportunities available to students enrolled in geoscience programs, and early-career geoscientists entering the workforce,” Wilson said. “Plus, this is the first time we have seen a major shift in employment patterns in over a generation, with increasing number of bachelor recipients securing geoscience positions, and newly minted Master’s finding themselves in high demand.”

Gas injection probably triggered small earthquakes near Snyder, Texas

A new study correlates a series of small earthquakes near Snyder, Texas between 2006 and 2011 with the underground injection of large volumes of gas, primarily carbon dioxide (CO2) – a finding that is relevant to the process of capturing and storing CO2 underground.

Although the study suggests that underground injection of gas triggered the Snyder earthquakes, it also points out that similar rates of injections have not triggered comparable quakes in other fields, bolstering the idea that underground gas injection does not cause significant seismic events in many geologic settings.

No injuries or severe damage were reported from the quakes identified in the study.

The study represents the first time underground gas injection has been correlated with earthquakes greater than magnitude 3.

The results, from Wei Gan and Cliff Frohlich at The University of Texas at Austin’s Institute for Geophysics, appear this week in an online edition of the journal Proceedings of the National Academy of Sciences.

The study focused on an area of northwest Texas with three large oil and gas fields – the Cogdell field, the Salt Creek field and the Scurry Area Canyon Reef Operators Committee unit (SACROC) – which have all produced petroleum since the 1950s.

Operators began injecting CO2 in the SACROC field in 1971 to boost petroleum production, a process known as CO2 Enhanced Oil Recovery (CO2 EOR). Operators began CO2 EOR in the Cogdell field in 2001, with a significant increase starting in 2004. Because CO2 has been injected at large volumes for many years, the Department of Energy has funded research in this region to explore the potential impacts of carbon capture and storage (CCS), a proposed technique for reducing greenhouse gas emissions by capturing CO2 and injecting it deep underground for long-term storage.

This latest study was funded by the U.S. Geological Survey and the National Natural Science Foundation of China.

Using a high-resolution temporary network of seismometers, Gan and Frohlich identified 93 earthquakes in the Cogdell area from March 2009 to December 2010, three of which were greater than magnitude 3. An even larger earthquake, with magnitude 4.4, occurred in Cogdell in September 2011. Using data on injections and extractions of fluids and gases, they concluded that the earthquakes were correlated with the increase in CO2 EOR in Cogdell.

“What’s interesting is we have an example in Cogdell field, but there are other fields nearby that have experienced similar CO2 flooding without triggering earthquakes,” said Frohlich, associate director of the Institute for Geophysics, a research unit in the Jackson School of Geosciences. “So the question is: Why does it happen in one area and not others?”

In a paper published last year in the Proceedings of the National Academy of Sciences, Stanford University earthquake researchers Mark Zoback and Steven Gorelick argued “there is a high probability that earthquakes will be triggered by injection of large volumes of CO2″ during CCS.

“The fact that the different fields responded differently to CO2 injection and that no other gas injection sites in the world have been linked to earthquakes with magnitudes as large as 3 suggest that despite Zoback and Gorelick’s concerns, it is possible that in many locations large-volume CO2 injection may not induce earthquakes,” said Frohlich.

Frohlich suggests one possible explanation for the different response to gas injection in the three fields might be that there are geological faults in the Cogdell area that are primed and ready to move when pressures from large volumes of gas reduce friction on these faults. The other two fields might not have such faults.

Frohlich suggests an important next step in understanding seismic risks for proposed CCS projects would be to create geological models of Cogdell and other nearby fields to better understand why they respond differently to gas injection.

Gan and Frohlich analyzed seismic data collected between March 2009 and December 2010 by the EarthScope USArray Program, a National Science Foundation-funded network of broadband seismometers deployed from the Canadian border to the Gulf of Mexico. Because of the high density of instruments, they were able to detect earthquakes down to magnitude 1.5, too weak for people to feel at the surface and many of which were not detected by the U.S. Geological Survey’s more limited seismic network.

Using the USArray data, the researchers identified and located 93 well-recorded earthquakes. Most occurred in several northeast-southwest trending linear clusters, which might indicate the presence of previously unidentified faults. Three of the quakes identified in the USArray data were greater than magnitude 3. According to U.S. Geological Survey observations for the same area from 2006 to 2011, 18 earthquakes greater than magnitude 3 occurred in the study area.

Gan and Frohlich also evaluated data on injections and extractions of oil, water and gas in the study area collected by the Texas Railroad Commission, the state agency that regulates oil and gas operations. Since 1990, rates of liquid injection and extraction, as well as gas produced, remained fairly constant in all three oil and gas fields. The only significant change was a substantial increase in injection rates of gas, primarily CO2, in the Cogdell field starting in 2004.

Previous work by Frohlich and others has shown that underground injection of liquids can induce earthquakes.

Gas injection probably triggered small earthquakes near Snyder, Texas

A new study correlates a series of small earthquakes near Snyder, Texas between 2006 and 2011 with the underground injection of large volumes of gas, primarily carbon dioxide (CO2) – a finding that is relevant to the process of capturing and storing CO2 underground.

Although the study suggests that underground injection of gas triggered the Snyder earthquakes, it also points out that similar rates of injections have not triggered comparable quakes in other fields, bolstering the idea that underground gas injection does not cause significant seismic events in many geologic settings.

No injuries or severe damage were reported from the quakes identified in the study.

The study represents the first time underground gas injection has been correlated with earthquakes greater than magnitude 3.

The results, from Wei Gan and Cliff Frohlich at The University of Texas at Austin’s Institute for Geophysics, appear this week in an online edition of the journal Proceedings of the National Academy of Sciences.

The study focused on an area of northwest Texas with three large oil and gas fields – the Cogdell field, the Salt Creek field and the Scurry Area Canyon Reef Operators Committee unit (SACROC) – which have all produced petroleum since the 1950s.

Operators began injecting CO2 in the SACROC field in 1971 to boost petroleum production, a process known as CO2 Enhanced Oil Recovery (CO2 EOR). Operators began CO2 EOR in the Cogdell field in 2001, with a significant increase starting in 2004. Because CO2 has been injected at large volumes for many years, the Department of Energy has funded research in this region to explore the potential impacts of carbon capture and storage (CCS), a proposed technique for reducing greenhouse gas emissions by capturing CO2 and injecting it deep underground for long-term storage.

This latest study was funded by the U.S. Geological Survey and the National Natural Science Foundation of China.

Using a high-resolution temporary network of seismometers, Gan and Frohlich identified 93 earthquakes in the Cogdell area from March 2009 to December 2010, three of which were greater than magnitude 3. An even larger earthquake, with magnitude 4.4, occurred in Cogdell in September 2011. Using data on injections and extractions of fluids and gases, they concluded that the earthquakes were correlated with the increase in CO2 EOR in Cogdell.

“What’s interesting is we have an example in Cogdell field, but there are other fields nearby that have experienced similar CO2 flooding without triggering earthquakes,” said Frohlich, associate director of the Institute for Geophysics, a research unit in the Jackson School of Geosciences. “So the question is: Why does it happen in one area and not others?”

In a paper published last year in the Proceedings of the National Academy of Sciences, Stanford University earthquake researchers Mark Zoback and Steven Gorelick argued “there is a high probability that earthquakes will be triggered by injection of large volumes of CO2″ during CCS.

“The fact that the different fields responded differently to CO2 injection and that no other gas injection sites in the world have been linked to earthquakes with magnitudes as large as 3 suggest that despite Zoback and Gorelick’s concerns, it is possible that in many locations large-volume CO2 injection may not induce earthquakes,” said Frohlich.

Frohlich suggests one possible explanation for the different response to gas injection in the three fields might be that there are geological faults in the Cogdell area that are primed and ready to move when pressures from large volumes of gas reduce friction on these faults. The other two fields might not have such faults.

Frohlich suggests an important next step in understanding seismic risks for proposed CCS projects would be to create geological models of Cogdell and other nearby fields to better understand why they respond differently to gas injection.

Gan and Frohlich analyzed seismic data collected between March 2009 and December 2010 by the EarthScope USArray Program, a National Science Foundation-funded network of broadband seismometers deployed from the Canadian border to the Gulf of Mexico. Because of the high density of instruments, they were able to detect earthquakes down to magnitude 1.5, too weak for people to feel at the surface and many of which were not detected by the U.S. Geological Survey’s more limited seismic network.

Using the USArray data, the researchers identified and located 93 well-recorded earthquakes. Most occurred in several northeast-southwest trending linear clusters, which might indicate the presence of previously unidentified faults. Three of the quakes identified in the USArray data were greater than magnitude 3. According to U.S. Geological Survey observations for the same area from 2006 to 2011, 18 earthquakes greater than magnitude 3 occurred in the study area.

Gan and Frohlich also evaluated data on injections and extractions of oil, water and gas in the study area collected by the Texas Railroad Commission, the state agency that regulates oil and gas operations. Since 1990, rates of liquid injection and extraction, as well as gas produced, remained fairly constant in all three oil and gas fields. The only significant change was a substantial increase in injection rates of gas, primarily CO2, in the Cogdell field starting in 2004.

Previous work by Frohlich and others has shown that underground injection of liquids can induce earthquakes.

Rising mountains, cooling oceans prompted spread of invasive species 450 million years ago

This slab of rock contains fossils of invasive species that populated the continent of Laurentia 450 million years ago after a major ecological shift occurred. Ohio University geologists found that rising mountains and cooling oceans prompted the spread of these invasive species. -  Alycia Stigall
This slab of rock contains fossils of invasive species that populated the continent of Laurentia 450 million years ago after a major ecological shift occurred. Ohio University geologists found that rising mountains and cooling oceans prompted the spread of these invasive species. – Alycia Stigall

New Ohio University research suggests that the rise of an early phase of the Appalachian Mountains and cooling oceans allowed invasive species to upset the North American ecosystem 450 million years ago.

The study, published recently in the journal PLOS ONE, took a closer look at a dramatic ecological shift captured in the fossil record during the Ordovician period. Ohio University scientists argue that major geological developments triggered evolutionary changes in the ancient seas, which were dominated by organisms such as brachiopods, corals, trilobites and crinoids.

During this period, North America was part of an ancient continent called Laurentia that sat near the equator and had a tropical climate. Shifting of the Earth’s tectonic plates gave rise to the Taconic Mountains, which were forerunners of the Appalachian Mountains. The geological shift left a depression behind the mountain range, flooding the area with cool water from the surrounding deep ocean.

Scientists knew that there was a massive influx of invasive species into this ocean basin during this time period, but didn’t know where the invaders came from or how they got a foothold in the ecosystem, said Alycia Stigall, an Ohio University associate professor of geological sciences who co-authored the paper with former Ohio University graduate student David Wright, now a doctoral student at Ohio State University.

“The rocks of this time record a major oceanographic shift, pulse of mountain building and a change in evolutionary dynamics coincident with each other,” Stigall said. “We are interested in examining the interactions between these factors.”

Using the fossils of 53 species of brachiopods that dominated the Laurentian ecosystem, Stigall and Wright created several phylogenies, or trees of reconstructed evolutionary relationships, to examine how individual speciation events occurred.

The invaders that proliferated during this time period were species within the groups of animals that inhabited Laurentia, Stigall explained. Within the brachiopods, corals and cephalopods, for example, some species are invasive and some are not.

As the geological changes slowly played out over the course of a million years, two patterns of survival emerged, the scientists report.

During the early stage of mountain building and ocean cooling, the native organisms became geographically divided, slowly evolving into different species suited for these niche habitats. This process, called vicariance, is the typical method by which new species originate on Earth, Stigall said.

As the geological changes progressed, however, species from other regions of the continent began to directly invade habitats, a process called dispersal. Although biodiversity may initially increase, this process decreases biodiversity in the long term, Stigall explained, because it allows a few aggressive species to populate many sites quickly, dominating those ecosystems.

This is the second time that Stigall and her team have found this pattern of speciation in the geological record. A study published in 2010 on the invasive species that prompted a mass extinction during the Devonian period about 375 million years ago also discovered a shift from vicariance to dispersal that contributed to a decline in biodiversity, Stigall noted.

It’s a pattern that’s happening during our modern biodiversity crisis as well, she said.

“Only one out of 10 invaders truly become invasive species. Understanding the process can help determine where to put conservation resources,” she said.

Rising mountains, cooling oceans prompted spread of invasive species 450 million years ago

This slab of rock contains fossils of invasive species that populated the continent of Laurentia 450 million years ago after a major ecological shift occurred. Ohio University geologists found that rising mountains and cooling oceans prompted the spread of these invasive species. -  Alycia Stigall
This slab of rock contains fossils of invasive species that populated the continent of Laurentia 450 million years ago after a major ecological shift occurred. Ohio University geologists found that rising mountains and cooling oceans prompted the spread of these invasive species. – Alycia Stigall

New Ohio University research suggests that the rise of an early phase of the Appalachian Mountains and cooling oceans allowed invasive species to upset the North American ecosystem 450 million years ago.

The study, published recently in the journal PLOS ONE, took a closer look at a dramatic ecological shift captured in the fossil record during the Ordovician period. Ohio University scientists argue that major geological developments triggered evolutionary changes in the ancient seas, which were dominated by organisms such as brachiopods, corals, trilobites and crinoids.

During this period, North America was part of an ancient continent called Laurentia that sat near the equator and had a tropical climate. Shifting of the Earth’s tectonic plates gave rise to the Taconic Mountains, which were forerunners of the Appalachian Mountains. The geological shift left a depression behind the mountain range, flooding the area with cool water from the surrounding deep ocean.

Scientists knew that there was a massive influx of invasive species into this ocean basin during this time period, but didn’t know where the invaders came from or how they got a foothold in the ecosystem, said Alycia Stigall, an Ohio University associate professor of geological sciences who co-authored the paper with former Ohio University graduate student David Wright, now a doctoral student at Ohio State University.

“The rocks of this time record a major oceanographic shift, pulse of mountain building and a change in evolutionary dynamics coincident with each other,” Stigall said. “We are interested in examining the interactions between these factors.”

Using the fossils of 53 species of brachiopods that dominated the Laurentian ecosystem, Stigall and Wright created several phylogenies, or trees of reconstructed evolutionary relationships, to examine how individual speciation events occurred.

The invaders that proliferated during this time period were species within the groups of animals that inhabited Laurentia, Stigall explained. Within the brachiopods, corals and cephalopods, for example, some species are invasive and some are not.

As the geological changes slowly played out over the course of a million years, two patterns of survival emerged, the scientists report.

During the early stage of mountain building and ocean cooling, the native organisms became geographically divided, slowly evolving into different species suited for these niche habitats. This process, called vicariance, is the typical method by which new species originate on Earth, Stigall said.

As the geological changes progressed, however, species from other regions of the continent began to directly invade habitats, a process called dispersal. Although biodiversity may initially increase, this process decreases biodiversity in the long term, Stigall explained, because it allows a few aggressive species to populate many sites quickly, dominating those ecosystems.

This is the second time that Stigall and her team have found this pattern of speciation in the geological record. A study published in 2010 on the invasive species that prompted a mass extinction during the Devonian period about 375 million years ago also discovered a shift from vicariance to dispersal that contributed to a decline in biodiversity, Stigall noted.

It’s a pattern that’s happening during our modern biodiversity crisis as well, she said.

“Only one out of 10 invaders truly become invasive species. Understanding the process can help determine where to put conservation resources,” she said.

Devastating long-distance impact of earthquakes

In 2006 the island of Java, Indonesia was struck by a devastating earthquake followed by the onset of a mud eruption to the east, flooding villages over several square kilometers and that continues to erupt today. Until now, researchers believed the earthquake was too far from the mud volcano to trigger the eruption. Geophysicists at the University of Bonn, Germany and ETH Zurich, Switzerland use computer-based simulations to show that such triggering is possible over long distances. The results have been published in “Nature Geoscience.”

On May 27, 2006 the ground of the Indonesian island Java was shaking with a magnitude 6.3 earthquake. The epicenter was located 25 km southwest of the city of Yogyakarta and initiated at a depth of 12 km. The earthquake took thousands of lives, injured ten thousand and destroyed buildings and homes. 47 hours later, about 250 km from the earthquake hypocenter, a mud volcano formed that came to be known as “Lusi”, short for “Lumpur Sidoarjo”. Hot mud erupted in the vicinity of an oil drilling-well, shooting mud up to 50 m into the sky and flooding the area. Scientists expect the mud volcano to be active for many more years.

Eruption of mud volcano has natural cause

Was the eruption of the mud triggered by natural events or was it man-made by the nearby exploration-well? Geophysicists at the University of Bonn, Germany and at ETH Zürich, Switzerland investigated this question with numerical wave-propagation experiments. “Many researchers believed that the earthquake epicenter was too far from Lusi to have activated the mud volcano,” says Prof. Dr. Stephen A. Miller from the department of Geodynamics at the University of Bonn. However, using their computer simulations that include the geological features of the Lusi subsurface, the team of Stephen Miller concluded that the earthquake was the trigger, despite the long distance.

The overpressured solid mud layer was trapped between layers with different acoustic properties, and this system was shaken from the earthquake and aftershocks like a bottle of champagne. The key, however, is the reflections provided by the dome-shaped geology underneath Lusi that focused the seismic waves of the earthquakes like the echo inside a cave. Prof. Stephen Miller explains: “Our simulations show that the dome-shaped structure with different properties focused seismic energy into the mud layer and could very well have liquified the mud that then injected into nearby faults.”

Previous studies would have underestimated the energy of the seismic waves, as ground motion was only considered at the surface. However, geophysicists at the University of Bonn suspect that those were much less intense than at depth. The dome-like structure “kept” the seismic waves at depth and damped those that reached the surface. “This was actually a lower estimate of the focussing effect because only one wave cycle was input. This effect increases with each wave cycle because of the reducing acoustic impedance of the pressurizing mud layer”. In response to claims that the reported highest velocity layer used in the modeling is a measurement artifact, Miller says “that does not change our conclusions because this effect will occur whenever a layer of low acoustic impedance is sandwiched between high impedance layers, irrespective of the exact values of the impedances. And the source of the Lusi mud was the inside of the sandwich.”

It has already been proposed that a tectonic fault is connecting Lusi to a 15 km distant volcanic system. Prof. Miller explains “This connection probably supplies the mud volcano with heat and fluids that keep Lusi erupting actively up to today”, explains Miller.

With their publication, scientists from Bonn and Zürich point out, that earthquakes can trigger processes over long distances, and this focusing effect may apply to other hydrothermal and volcanic systems. Stephen Miller concludes: “Being a geological rarity, the mud volcano may contribute to a better understanding of triggering processes and relationships between seismic and volcanic activity.” Miller also adds “maybe this work will settle the long-standing controversy and focus instead on helping those affected.” The island of Java is part of the so called Pacific Ring of Fire, a volcanic belt which surrounds the entire Pacific Ocean. Here, oceanic crust is subducted underneath oceanic and continental tectonic plates, leading to melting of crustal material at depth. The resulting magma uprises and is feeding numerous volcanoes.

Devastating long-distance impact of earthquakes

In 2006 the island of Java, Indonesia was struck by a devastating earthquake followed by the onset of a mud eruption to the east, flooding villages over several square kilometers and that continues to erupt today. Until now, researchers believed the earthquake was too far from the mud volcano to trigger the eruption. Geophysicists at the University of Bonn, Germany and ETH Zurich, Switzerland use computer-based simulations to show that such triggering is possible over long distances. The results have been published in “Nature Geoscience.”

On May 27, 2006 the ground of the Indonesian island Java was shaking with a magnitude 6.3 earthquake. The epicenter was located 25 km southwest of the city of Yogyakarta and initiated at a depth of 12 km. The earthquake took thousands of lives, injured ten thousand and destroyed buildings and homes. 47 hours later, about 250 km from the earthquake hypocenter, a mud volcano formed that came to be known as “Lusi”, short for “Lumpur Sidoarjo”. Hot mud erupted in the vicinity of an oil drilling-well, shooting mud up to 50 m into the sky and flooding the area. Scientists expect the mud volcano to be active for many more years.

Eruption of mud volcano has natural cause

Was the eruption of the mud triggered by natural events or was it man-made by the nearby exploration-well? Geophysicists at the University of Bonn, Germany and at ETH Zürich, Switzerland investigated this question with numerical wave-propagation experiments. “Many researchers believed that the earthquake epicenter was too far from Lusi to have activated the mud volcano,” says Prof. Dr. Stephen A. Miller from the department of Geodynamics at the University of Bonn. However, using their computer simulations that include the geological features of the Lusi subsurface, the team of Stephen Miller concluded that the earthquake was the trigger, despite the long distance.

The overpressured solid mud layer was trapped between layers with different acoustic properties, and this system was shaken from the earthquake and aftershocks like a bottle of champagne. The key, however, is the reflections provided by the dome-shaped geology underneath Lusi that focused the seismic waves of the earthquakes like the echo inside a cave. Prof. Stephen Miller explains: “Our simulations show that the dome-shaped structure with different properties focused seismic energy into the mud layer and could very well have liquified the mud that then injected into nearby faults.”

Previous studies would have underestimated the energy of the seismic waves, as ground motion was only considered at the surface. However, geophysicists at the University of Bonn suspect that those were much less intense than at depth. The dome-like structure “kept” the seismic waves at depth and damped those that reached the surface. “This was actually a lower estimate of the focussing effect because only one wave cycle was input. This effect increases with each wave cycle because of the reducing acoustic impedance of the pressurizing mud layer”. In response to claims that the reported highest velocity layer used in the modeling is a measurement artifact, Miller says “that does not change our conclusions because this effect will occur whenever a layer of low acoustic impedance is sandwiched between high impedance layers, irrespective of the exact values of the impedances. And the source of the Lusi mud was the inside of the sandwich.”

It has already been proposed that a tectonic fault is connecting Lusi to a 15 km distant volcanic system. Prof. Miller explains “This connection probably supplies the mud volcano with heat and fluids that keep Lusi erupting actively up to today”, explains Miller.

With their publication, scientists from Bonn and Zürich point out, that earthquakes can trigger processes over long distances, and this focusing effect may apply to other hydrothermal and volcanic systems. Stephen Miller concludes: “Being a geological rarity, the mud volcano may contribute to a better understanding of triggering processes and relationships between seismic and volcanic activity.” Miller also adds “maybe this work will settle the long-standing controversy and focus instead on helping those affected.” The island of Java is part of the so called Pacific Ring of Fire, a volcanic belt which surrounds the entire Pacific Ocean. Here, oceanic crust is subducted underneath oceanic and continental tectonic plates, leading to melting of crustal material at depth. The resulting magma uprises and is feeding numerous volcanoes.

Scientist finds topography of Eastern Seaboard muddles ancient sea level changes

The distortion of the ancient shoreline and flooding surface of the U.S. Atlantic Coastal Plain are the direct result of fluctuations in topography in the region and could have implications on understanding long-term climate change, according to a new study.

Sedimentary rocks from Virginia through Florida show marine flooding during the mid-Pliocene Epoch, which correlates to approximately 4 million years ago. Several wave-cut scarps, (rock exposures) which originally would have been horizontal, are now draped over a warped surface with up to 60 meters variation.

Nathan Simmons of Lawrence Livermore National Laboratory and colleagues from the University of Chicago, Université du Québec à Montréal, Syracuse University, Harvard University and the University of Texas at Austin modeled the active topography using mantle convection simulations that predict the amplitude and broad spatial distribution of this distortion. The results imply that dynamic topography and, to a lesser extent, glacial adjustment, account for the current architecture of the coastal plain and nearby shelf.

The results appear in the May 16 edition of Science Express, and will appear at a later date in Science Magazine,

“Our simulations of dynamic topography of the Eastern Seaboard have implications for inferences of global long-term sea-level change,” Simmons said.

The eastern coast of the United States is considered an archetypal Atlantic-type or passive-type continental margin.

“The highlight is that mantle flow is a major component in distorting the Earth’s surface over geologic time, even in so-called ‘passive’ continental margins,” Simmons said. “Reconstructing long-term global sea-level change based on stratigraphic relations must account for this effect. In other words, did the water level change or did the ground move? This could have implications on understanding very long-term climate change.”

The mantle is not a passive player in determining long-term sea level changes. Mantle flow influences surface topography, through perturbations of the dynamic topography, in a manner that varies both spatially and temporally. As a result, it is it difficult to invert for the global long-term sea level signal and, in turn, the size of the Antarctic Ice Sheet, using east coast shoreline data.

Simmons said the new results provide another powerful piece of evidence that mantle flow is intimately involved in shaping the Earth’s surface and must be considered when attempting to unravel numerous long-term Earth processes such as sea-level variations over millions of years.

Scientist finds topography of Eastern Seaboard muddles ancient sea level changes

The distortion of the ancient shoreline and flooding surface of the U.S. Atlantic Coastal Plain are the direct result of fluctuations in topography in the region and could have implications on understanding long-term climate change, according to a new study.

Sedimentary rocks from Virginia through Florida show marine flooding during the mid-Pliocene Epoch, which correlates to approximately 4 million years ago. Several wave-cut scarps, (rock exposures) which originally would have been horizontal, are now draped over a warped surface with up to 60 meters variation.

Nathan Simmons of Lawrence Livermore National Laboratory and colleagues from the University of Chicago, Université du Québec à Montréal, Syracuse University, Harvard University and the University of Texas at Austin modeled the active topography using mantle convection simulations that predict the amplitude and broad spatial distribution of this distortion. The results imply that dynamic topography and, to a lesser extent, glacial adjustment, account for the current architecture of the coastal plain and nearby shelf.

The results appear in the May 16 edition of Science Express, and will appear at a later date in Science Magazine,

“Our simulations of dynamic topography of the Eastern Seaboard have implications for inferences of global long-term sea-level change,” Simmons said.

The eastern coast of the United States is considered an archetypal Atlantic-type or passive-type continental margin.

“The highlight is that mantle flow is a major component in distorting the Earth’s surface over geologic time, even in so-called ‘passive’ continental margins,” Simmons said. “Reconstructing long-term global sea-level change based on stratigraphic relations must account for this effect. In other words, did the water level change or did the ground move? This could have implications on understanding very long-term climate change.”

The mantle is not a passive player in determining long-term sea level changes. Mantle flow influences surface topography, through perturbations of the dynamic topography, in a manner that varies both spatially and temporally. As a result, it is it difficult to invert for the global long-term sea level signal and, in turn, the size of the Antarctic Ice Sheet, using east coast shoreline data.

Simmons said the new results provide another powerful piece of evidence that mantle flow is intimately involved in shaping the Earth’s surface and must be considered when attempting to unravel numerous long-term Earth processes such as sea-level variations over millions of years.