Geologists dig into science around the globe, on land and at sea

University of Cincinnati geologists will be well represented among geoscientists from around the world at The Geological Society of America’s Annual Meeting and Exposition. The meeting takes place Oct. 19-22, in Vancouver, Canada, and will feature geoscientists representing more than 40 different disciplines. The meeting will feature highlights of UC’s geological research that is taking place globally, from Chile to Costa Rica, Belize, Bulgaria, Scotland, Trinidad and a new project under development in the Canary Islands.

UC faculty and graduate students are lead or supporting authors on more than two dozen Earth Sciences-related research papers and/or PowerPoint and poster exhibitions at the GSA meeting.

The presentations also cover UC’s longtime and extensive exploration and findings in the Cincinnati Arch of the Ohio Valley, world-renowned for its treasure trove of paleontology – plant and animal fossils that were preserved when a shallow sea covered the region 450 million years ago during the Paleozoic Era.

Furthermore, in an effort to diversify the field of researchers in the Earth Sciences, a UC assistant professor of science education and geology, Christopher Atchison, was awarded funding from the National Science Foundation and the Society of Exploration Geophysics to lead a research field trip in Vancouver for students with disabilities. Graduate and undergraduate student participants will conduct the research on Oct. 18 and then join events at the GSA meeting. They’ll be guided by geoscience researchers representing the United Kingdom, New Zealand, Canada and the U.S. Those guides include Atchison and Julie Hendricks, a UC special education major from Batavia, Ohio, who will be using her expertise in American Sign Language (ASL) to assist student researchers representing Deaf and Hard of Hearing communities.

The meeting will also formally introduce Arnold Miller, UC professor of geology, as the new president-elect of the national Paleontological Society Thomas Lowell, professor of geology, is a recently elected Fellow of the Geological Society of America – a recognition for producing a substantial body of research. Lowell joins colleagues Warren Huff, professor of geology, and Lewis Owen, professor and head of the Department of Geology, as GSA Fellows.

Here are highlights of the UC research to be presented at the GSA meeting Oct. 19-22:

Staying Put or Moving On? Researchers Develop Model to Identify Migrating Patterns of Different Species

Are plant and animal species what you might call lifelong residents – they never budge from the same place? That’s a relatively common belief in ecology and paleoecology – that classes of organisms tend to stay put over millions of years and either evolve or go extinct as the environment changes. UC researchers developed a series of numerical models simulating shifting habitats in fossil regions to compare whether species changed environments when factoring geological and other changes in the fossil record. They found that geologically driven changes in the quality of the fossil record did not distort the real ecological signal, and that most species maintained their particular habitat preferences through time. They did not evolve to adapt to changing environments, but rather, they migrated, following their preferred environments. That is to say, they did not stay in place geographically but by moving, they were able to track their favored habitats. Field research for the project was conducted in New York state as well as the paleontological-rich region of Cincinnati; Dayton, Ohio, Lexington, Ky.; and Indiana. Funding for the project was supported by The Paleontological Society; The Geological Society of America; The American Museum of Natural History and the UC Geology Department’s Kenneth E. Caster Memorial Fund.

Presenter: Andrew Zaffos, UC geology doctoral student

Co-authors: Arnold Miller, Carlton Brett

Pioneering Study Provides a Better Understanding of What Southern Ohio and Central Kentucky Looked Like Hundreds of Millions of Years Ago

The end of the Ordovician period resulted in one of the largest mass extinction events in the Earth’s history. T.J. Malgieri, a UC master’s student in geology, led this study examining the limestone and shales of the Upper Ordovician Period – the geologic Grant Lake Formation covering southern Ohio and central Kentucky – to recreate how the shoreline looked some 445 million years ago. In this pioneering study of mud cracks and deposits in the rocks, the researchers discovered that the shoreline existed to the south and that the water became deeper toward the north. By determining these ecological parameters, the ramp study provides a better understanding of environments during a time of significant ecological change. Malgieri says the approach can be applied to other basins throughout the world to create depth indicators in paeloenvironments.

Presenter: T.J. Malgieri, UC geology master’s student

Co-authors: Carlton Brett, Cameron Schalbach, Christopher Aucoin, UC; James Thomka (UC, University of Akron); Benjamin Dattilo, Indiana University Purdue University Ft. Wayne

UC Researchers Take a Unique Approach to Monitoring Groundwater Supplies Near Ohio Fracking Sites

A collaborative research project out of UC is examining effects of fracking on groundwater in the Utica Shale region of eastern Ohio. First launched in Carroll County in 2012, the team of researchers is examining methane levels and origins of methane in private wells and springs before, during and after the onset of fracking. The team travels to the region to take water samples four times a year.

Presenter: Claire Botner, a UC geology master’s student

Co-author: Amy Townsend-Small, UC assistant professor of geology

Sawing Through Seagrass to Reveal Clues to the Past

Kelsy Feser, a UC doctoral student in geology, is working at several sites around St. Croix in the Virgin Islands to see if human developments impact marine life. The research focuses on shells of snails and clams that have piled up on the sea floor for thousands of years. Digging through layers of thick seagrass beds on the ocean floor, Feser can examine deeper shells that were abundant thousands of years ago and compare them to shallower layers that include living clams and snails. Early analysis indicates a greater population of potentially pollution-tolerant mussels in an area near a landfill on the island, compared with shells from much earlier time periods. Feser is doing this sea grass analysis around additional sites including tourist resorts, an oil refinery, a power plant and a marina. Funding for the research is provided by the Paleontological Society, the GSA, the American Museum of Natural History and the UC Geology Department.

Presenter: Kelsy Feser, UC geology doctoral student

Co-authors: Arnold Miller

Turning to the Present to Understand the Past

In order to properly interpret changes in climate, vegetation, or animal populations over time, it is necessary to establish a comparative baseline. Stella Mosher, a UC geology master’s student, is studying stable carbon, nitrogen, sulfur and strontium isotopes in modern vegetation from the Canary Islands in order to quantify modern climatic and environmental patterns. Her findings will provide a crucial foundation for future UC research on regional paleoclimatic and paleoenvironmental shifts.

Presenter: Stella Mosher, graduate student in geology

Co-authors: Brooke Crowley, assistant professor of geology; Yurena Yanes, research assistant professor of geology

A Study on the Impact of Sea Spray

Sulfur is an element of interest in both geology and archaeology, because it can reveal information about the diets of ancient cultures. This study takes a novel approach to studying how sea spray can affect the sulfur isotope values in plants on a small island, focusing on the island of Trinidad. Researchers collected leaves from different plant species to get their sulfur isotope value, exploring whether wind direction played a role in how plants were influenced by the marine water from sea spray. Vegetation was collected from the edges of the island to the deeply forested areas. The study found that sulfur isotope values deeper inland and on the calmer west coast were dramatically lower in indicating marine water than vegetation along the edges and the east coast. The findings can help indicate the foraging activities of humans and animals. Funding for the study was supported by the Geological Society of America, the UC Graduate Student Association and the UC Department of Geology.

Presenter: Janine Sparks, UC geology doctoral student

Co-authors: Brooke Crowley, UC assistant professor, geology/anthropology; William Gilhooly III, assistant professor, Earth Sciences, Indiana University-Purdue University Indianapolis

Proxy Wars – The Paleobiology Data Debate

For the past several decades, paleobiologists have built large databases containing information on fossil plants and animals of all geological ages to investigate the timing and extent of major changes in biodiversity – changes such as mass extinctions that have taken place throughout the history of life. Biodiversity researcher Arnold Miller says that in building these databases, it can be a challenge to accurately identify species in the geological record, so it has been common for researchers to instead study biodiversity trends using data compiled at broader levels of biological classification, including the genus level, under the assumption that these patterns are effective proxies for what would be observed among species if the data were available. Miller has been involved in construction of The Paleobiology Database, an extensive public online resource that contains global genus- and species-level data, now permitting a direct, novel look at the similarities and differences between patterns at these two levels. Miller’s discussion aims to set the record straight as to when researchers can effectively use a genus as a proxy for a species and also when it’s inappropriate. This research is funded by the NASA Astrobiology Program.

Presenter: Arnold Miller, UC professor of geology

A Novel New Method for Examining the Distribution of Pores in Rocks

Oil and gas companies take an interest in the porosity of sedimentary rocks because those open spaces can be filled with fuel resources. Companies involved with hydraulic fracturing (“fracking”) are also interested in porosity because it could be a source for storing wastewater as a result of fracking. In this unique study, UC researchers made pore-size measurements similar to those used in crystal size distribution (CSD) theory to determine distribution of pores as a function of their sizes, using thin sections of rock. In addition to providing accurate porosity distribution at a given depth, their approach can be extended to evaluate variation of pore spaces as a function of depth in a drill core, percent of pores in each size range, and pore types and pore geometry. The Texas Bureau of Economic Geology provided the rock samples used in the study. Funding for the study was supported by the Turkish Petroleum Corporation.

Presenter: Ugurlu Ibrahim, master’s student in geology

Co-author: Attila Kilinc, professor of geology

Researchers Turn to 3-D Technology to Examine the Formation of Cliffband Landscapes

A blend of photos and technology takes a new twist on studying cliff landscapes and how they were formed. The method called Structure-From-Motion Photogrammetry – computational photo image processing techniques – is used to study the formation of cliff landscapes in Colorado and Utah and to understand how the layered rock formations in the cliffs are affected by erosion.

Presenter: Dylan Ward, UC assistant professor of geology

Testing the Links Between Climate and Sedimentation in the Atacama Desert, Northern Chile

The Atacama Desert is used as an analog for understanding the surface of Mars. In some localities, there has been no activity for millions of years. UC researchers have been working along the flank of the Andes Mountains in northern Chile, and this particular examination focuses on the large deposits of sediment that are transported down the plateau and gather at the base. The researchers are finding that their samples are not reflecting the million-year-old relics previously found on such expeditions, but may indicate more youthful activity possibly resulting from climatic events. The research is supported by a $273,634 grant from the National Science Foundation to explore glacio-geomorphic constraints on the climate history of subtropical northern Chile.

Presenter: Jason Cesta, UC geology master’s student

Co-author: Dylan Ward, UC assistant professor of geology

Uncovering the Explosive Mysteries Surrounding the Manganese of Northeast Bulgaria

UC’s geology collections hold minerals from field expeditions around the world, including manganese from the Obrochishte mines of northeastern Bulgaria. Found in the region’s sedimentary rock, manganese can be added to metals such as steel to improve strength. It’s widely believed that these manganese formations were the result of ocean water composition at the time the sediments were deposited in the ocean. In this presentation, UC researchers present new information on why they believe the manganese formations resulted from volcanic eruptions, perhaps during the Rupelian stage of the geologic time scale, when bentonite clay minerals were formed. The presentation evolved from an advance class project last spring under the direction of Warren Huff, a UC professor of geology.

Presenter: Jason Cesta, UC geology master’s student

Co-authors: Warren Huff, UC professor of geology; Christopher Aucoin; Michael Harrell; Thomas Malgieri; Barry Maynard; Cameron Schwalbach; Ibrahim Ugurlu; Antony Winrod

Two UC researchers will chair sessions at the GSA meeting: Doctoral student Gary Motz will chair the session, “Topics in Paleoecology: Modern Analogues and Ancient Systems,” on Oct. 19. Matt Vrazo, also a doctoral student in geology, is chairing “Paleontology: Trace Fossils, Taphonomy and Exceptional Preservation” on Oct. 21, and will present, “Taphonomic and Ecological Controls on Eurypterid Lagerstäten: A Model for Preservation in the Mid-Paleozoic.”


UC’s nationally ranked Department of Geology conducts field research around the world in areas spanning paleontology, quaternary geology, geomorphology, sedimentology, stratigraphy, tectonics, environmental geology and biogeochemistry.

The Geological Society of America, founded in 1888, is a scientific society with more than 26,500 members from academia, government, and industry in more than 100 countries. Through its meetings, publications, and programs, GSA enhances the professional growth of its members and promotes the geosciences in the service of humankind.

Icebergs once drifted to Florida, new climate model suggests

This is a map showing the pathway taken by icebergs from Hudson Bay, Canada, to Florida. The blue colors (behind the arrows) are an actual snapshot from the authors' high resolution model showing how much less salty the water is than normal. The more blue the color the less salty it is than normal. In this case, blue all the way along the coast shows that very fresh, cold waters are flowing along the entire east coast from Hudson Bay to Florida. -  UMass Amherst
This is a map showing the pathway taken by icebergs from Hudson Bay, Canada, to Florida. The blue colors (behind the arrows) are an actual snapshot from the authors’ high resolution model showing how much less salty the water is than normal. The more blue the color the less salty it is than normal. In this case, blue all the way along the coast shows that very fresh, cold waters are flowing along the entire east coast from Hudson Bay to Florida. – UMass Amherst

Using a first-of-its-kind, high-resolution numerical model to describe ocean circulation during the last ice age about 21,000 year ago, oceanographer Alan Condron of the University of Massachusetts Amherst has shown that icebergs and meltwater from the North American ice sheet would have regularly reached South Carolina and even southern Florida. The models are supported by the discovery of iceberg scour marks on the sea floor along the entire continental shelf.

Such a view of past meltwater and iceberg movement implies that the mechanisms of abrupt climate change are more complex than previously thought, Condron says. “Our study is the first to show that when the large ice sheet over North America known as the Laurentide ice sheet began to melt, icebergs calved into the sea around Hudson Bay and would have periodically drifted along the east coast of the United States as far south as Miami and the Bahamas in the Caribbean, a distance of more than 3,100 miles, about 5,000 kilometers.”

His work, conducted with Jenna Hill of Coastal Carolina University, is described in the current advance online issue of Nature Geosciences. “Determining how far south of the subpolar gyre icebergs and meltwater penetrated is vital for understanding the sensitivity of North Atlantic Deep Water formation and climate to past changes in high-latitude freshwater runoff,” the authors say.

Hill analyzed high-resolution images of the sea floor from Cape Hatteras to Florida and identified about 400 scour marks on the seabed that were formed by enormous icebergs plowing through mud on the sea floor. These characteristic grooves and pits were formed as icebergs moved into shallower water and their keels bumped and scraped along the ocean floor.

“The depth of the scours tells us that icebergs drifting to southern Florida were at least 1,000 feet, or 300 meters thick,” says Condron. “This is enormous. Such icebergs are only found off the coast of Greenland today.”

To investigate how icebergs might have drifted as far south as Florida, Condron simulated the release of a series of glacial meltwater floods in his high-resolution ocean circulation model at four different levels for two locations, Hudson Bay and the Gulf of St. Lawrence.

Condron reports, “In order for icebergs to drift to Florida, our glacial ocean circulation model tells us that enormous volumes of meltwater, similar to a catastrophic glacial lake outburst flood, must have been discharging into the ocean from the Laurentide ice sheet, from either Hudson Bay or the Gulf of St. Lawrence.”

Further, during these large meltwater flood events, the surface ocean current off the coast of Florida would have undergone a complete, 180-degree flip in direction, so that the warm, northward flowing Gulf Stream would have been replaced by a cold, southward flowing current, he adds.

As a result, waters off the coast of Florida would have been only a few degrees above freezing. Such events would have led to the sudden appearance of massive icebergs along the east coast of the United States all the way to Florida Keys, Condron points out. These events would have been abrupt and short-lived, probably less than a year, he notes.

“This new research shows that much of the meltwater from the Greenland ice sheet may be redistributed by narrow coastal currents and circulate through subtropical regions prior to reaching the subpolar ocean. It’s a more complicated picture than we believed before,” Condron says. He and Hill say that future research on mechanisms of abrupt climate change should take into account coastal boundary currents in redistributing ice sheet runoff and subpolar fresh water.

Mystery solved: ‘Sailing stones’ of Death Valley seen in action for the first time

Racetrack Playa is home to an enduring Death Valley mystery. Littered across the surface of this dry lake, also called a “playa,” are hundreds of rocks – some weighing as much as 320 kilograms (700 pounds) – that seem to have been dragged across the ground, leaving synchronized trails that can stretch for hundreds of meters.

What powerful force could be moving them? Researchers have investigated this question since the 1940s, but no one has seen the process in action – until now.

In a paper published in the journal PLOS ONE on Aug. 27, a team led by Scripps Institution of Oceanography, UC San Diego, paleobiologist Richard Norris reports on first-hand observations of the phenomenon.

Because the stones can sit for a decade or more without moving, the researchers did not originally expect to see motion in person. Instead, they decided to monitor the rocks remotely by installing a high-resolution weather station capable of measuring gusts to one-second intervals and fitting 15 rocks with custom-built, motion-activated GPS units. (The National Park Service would not let them use native rocks, so they brought in similar rocks from an outside source.) The experiment was set up in winter 2011 with permission of the Park Service. Then – in what Ralph Lorenz of the Applied Physics Laboratory at the Johns Hopkins University, one of the paper’s authors, suspected would be “the most boring experiment ever” – they waited for something to happen.

But in December 2013, Norris and co-author and cousin Jim Norris arrived in Death Valley to discover that the playa was covered with a pond of water seven centimeters (three inches) deep. Shortly after, the rocks began moving.

“Science sometimes has an element of luck,” Richard Norris said. “We expected to wait five or ten years without anything moving, but only two years into the project, we just happened to be there at the right time to see it happen in person.”

Their observations show that moving the rocks requires a rare combination of events. First, the playa fills with water, which must be deep enough to form floating ice during cold winter nights but shallow enough to expose the rocks. As nighttime temperatures plummet, the pond freezes to form thin sheets of “windowpane” ice, which must be thin enough to move freely but thick enough to maintain strength. On sunny days, the ice begins to melt and break up into large floating panels, which light winds drive across the playa, pushing rocks in front of them and leaving trails in the soft mud below the surface.

“On Dec. 21, 2013, ice breakup happened just around noon, with popping and cracking sounds coming from all over the frozen pond surface,” said Richard Norris. “I said to Jim, ‘This is it!'”

These observations upended previous theories that had proposed hurricane-force winds, dust devils, slick algal films, or thick sheets of ice as likely contributors to rock motion. Instead, rocks moved under light winds of about 3-5 meters per second (10 miles per hour) and were driven by ice less than 3-5 millimeters (0.25 inches) thick, a measure too thin to grip large rocks and lift them off the playa, which several papers had proposed as a mechanism to reduce friction. Further, the rocks moved only a few inches per second (2-6 meters per minute), a speed that is almost imperceptible at a distance and without stationary reference points.

“It’s possible that tourists have actually seen this happening without realizing it,” said Jim Norris of the engineering firm Interwoof in Santa Barbara. “It is really tough to gauge that a rock is in motion if all the rocks around it are also moving.”

Individual rocks remained in motion for anywhere from a few seconds to 16 minutes. In one event, the researchers observed rocks three football fields apart began moving simultaneously and traveled over 60 meters (200 feet) before stopping. Rocks often moved multiple times before reaching their final resting place. The researchers also observed rock-less trails formed by grounding ice panels – features that the Park Service had previously suspected were the result of tourists stealing rocks.

“The last suspected movement was in 2006, and so rocks may move only about one millionth of the time,” said Lorenz. “There is also evidence that the frequency of rock movement, which seems to require cold nights to form ice, may have declined since the 1970s due to climate change.”

Richard and Jim Norris, and co-author Jib Ray of Interwoof started studying the Racetrack’s moving rocks to solve the “public mystery” and set up the “Slithering Stones Research Initiative” to engage a wide circle of friends in the effort. They needed the help of volunteers who repeatedly visited the remote dry lake, quarried the rocks that were fitted with GPS, and maintained custom-made instruments. Lorenz and Brian Jackson of the Department of Physics at Boise State University started working on the phenomenon for their own reasons: They wanted to study dust devils and other desert weather features that might have analogs to processes happening on other planets.

“What is striking about prior research on the Racetrack is that almost everybody was doing the work not to gain fame or fortune, but because it is such a neat problem,” said Jim Norris.

So is the mystery of the sliding rocks finally solved?

“We documented five movement events in the two and a half months the pond existed and some involved hundreds of rocks”, says Richard Norris, “So we have seen that even in Death Valley, famous for its heat, floating ice is a powerful force in rock motion. But we have not seen the really big boys move out there?.Does that work the same way?”

Modern ocean acidification is outpacing ancient upheaval, study suggests

<IMG SRC="/Images/964394569.jpg" WIDTH="350" HEIGHT="237" BORDER="0" ALT="The deep-sea benthic foram Aragonia velascoensis went extinct about 56 million years ago as the oceans rapidly acidified. – Ellen Thomas/Yale University”>
The deep-sea benthic foram Aragonia velascoensis went extinct about 56 million years ago as the oceans rapidly acidified. – Ellen Thomas/Yale University

Some 56 million years ago, a massive pulse of carbon dioxide into the atmosphere sent global temperatures soaring. In the oceans, carbonate sediments dissolved, some organisms went extinct and others evolved.

Scientists have long suspected that ocean acidification played a part in the crisis-similar to today, as manmade CO2 combines with seawater to change its chemistry. Now, for the first time, scientists have quantified the extent of surface acidification from those ancient days, and the news is not good: the oceans are on track to acidify at least as much as they did then, only at a much faster rate.

In a study published in the latest issue of Paleoceanography, the scientists estimate that surface ocean acidity increased by about 100 percent in a few thousand years or more, and stayed that way for the next 70,000 years. In this radically changed environment, some creatures died out while others adapted and evolved. The study is the first to use the chemical composition of fossils to reconstruct surface ocean acidity at the Paleocene-Eocene Thermal Maximum (PETM), a period of intense warming on land and throughout the oceans due to high CO2.

“This could be the closest geological analog to modern ocean acidification,” said study coauthor Bärbel Hönisch, a paleoceanographer at Columbia University’s Lamont-Doherty Earth Observatory. “As massive as it was, it still happened about 10 times more slowly than what we are doing today.”

The oceans have absorbed about a third of the carbon humans have pumped into the air since industrialization, helping to keep temperatures lower than they would be otherwise. But that uptake of carbon has come at a price. Chemical reactions caused by that excess CO2 have made seawater grow more acidic, depleting it of the carbonate ions that corals, mollusks and calcifying plankton need to build their shells and skeletons.

In the last 150 years or so, the pH of the oceans has dropped substantially, from 8.2 to 8.1–equivalent to a 25 percent increase in acidity. By the end of the century, ocean pH is projected to fall another 0.3 pH units, to 7.8. While the researchers found a comparable pH drop during the PETM–0.3 units–the shift happened over a few thousand years.

“We are dumping carbon in the atmosphere and ocean at a much higher rate today-within centuries,” said study coauthor Richard Zeebe, a paleoceanographer at the University of Hawaii. “If we continue on the emissions path we are on right now, acidification of the surface ocean will be way more dramatic than during the PETM.”

Ocean acidification in the modern ocean may already be affecting some marine life, as shown by the partly dissolved shell of this planktic snail, or pteropod, caught off the Pacific Northwest.

The study confirms that the acidified conditions lasted for 70,000 years or more, consistent with previous model-based estimates.

“It didn’t bounce back right away,” said Timothy Bralower, a researcher at Penn State who was not involved in the study. “It took tens of thousands of years to recover.”

From seafloor sediments drilled off Japan, the researchers analyzed the shells of plankton that lived at the surface of the ocean during the PETM. Two different methods for measuring ocean chemistry at the time-the ratio of boron isotopes in their shells, and the amount of boron –arrived at similar estimates of acidification. “It’s really showing us clear evidence of a change in pH for the first time,” said Bralower.

What caused the burst of carbon at the PETM is still unclear. One popular explanation is that an overall warming trend may have sent a pulse of methane from the seafloor into the air, setting off events that released more earth-warming gases into the air and oceans. Up to half of the tiny animals that live in mud on the seafloor-benthic foraminifera-died out during the PETM, possibly along with life further up the food chain.

Other species thrived in this changed environment and new ones evolved. In the oceans, dinoflagellates extended their range from the tropics to the Arctic, while on land, hoofed animals and primates appeared for the first time. Eventually, the oceans and atmosphere recovered as elements from eroded rocks washed into the sea and neutralized the acid.

Today, signs are already emerging that some marine life may be in trouble. In a recent study led by Nina Bednarsek at the U.S. National Oceanic and Atmospheric Administration, more than half of the tiny planktic snails, or pteropods, that she and her team studied off the coast of Washington, Oregon and California showed badly dissolved shells. Ocean acidification has been linked to the widespread death of baby oysters off Washington and Oregon since 2005, and may also pose a threat to coral reefs, which are under additional pressure from pollution and warming ocean temperatures.

“Seawater carbonate chemistry is complex but the mechanism underlying ocean acidification is very simple,” said study lead author Donald Penman, a graduate student at University of California at Santa Cruz. “We can make accurate predictions about how carbonate chemistry will respond to increasing carbon dioxide levels. The real unknown is how individual organisms will respond and how that cascades through ecosystems.”

Oil- and metal-munching microbes dominate deep sandstone formations

<IMG SRC="/Images/325645565.jpg" WIDTH="350" HEIGHT="245" BORDER="0" ALT="Halomonas bacteria are well-known for consuming the metal parts of the Titanic. Researchers now have found Halomonas in sandstone formations deep underground. – NOAA”>
Halomonas bacteria are well-known for consuming the metal parts of the Titanic. Researchers now have found Halomonas in sandstone formations deep underground. – NOAA

Halomonas are a hardy breed of bacteria. They can withstand heat, high salinity, low oxygen, utter darkness and pressures that would kill most other organisms. These traits enable these microbes to eke out a living in deep sandstone formations that also happen to be useful for hydrocarbon extraction and carbon sequestration, researchers report in a new study.

The analysis, the first unobstructed view of the microbial life of sandstone formations more than a mile below the surface, appears in the journal Environmental Microbiology.

“We are using new DNA technologies to understand the distribution of life in extreme natural environments,” said study leader Bruce Fouke, a professor of geology and of microbiology at the University of Illinois at Urbana-Champaign. Fouke also is an investigator with the Energy Biosciences Institute, which funded the research, and an affiliate of the Institute for Genomic Biology at Illinois.

Underground microbes are at least as diverse as their surface-dwelling counterparts, Fouke said, and that diversity has gone largely unstudied.

“Astonishingly little is known of this vast subsurface reservoir of biodiversity, despite our civilization’s regular access to and exploitation of subterranean environments,” he said.

To address this gap in knowledge, Fouke and his colleagues collected microbial samples from a sandstone reservoir 1.8 kilometers (1.1 miles) below the surface.

The team used a probe developed by the oilfield services company Schlumberger that reduces or eliminates contamination from mud and microbes at intermediate depths. The researchers sampled sandstone deposits of the Illinois Basin, a vast, subterranean bowl underlying much of Illinois and parts of Indiana, Kentucky and Tennessee, and a rich source of coal and oil.

A genomic study and analysis of the microbes the team recovered revealed “a low-diversity microbial community dominated by Halomonas sulfidaeris-like bacteria that have evolved several strategies to cope with and survive the high-pressure, high-temperature and nutrient deprived deep subsurface environment,” Fouke said.

An analysis of the microbes’ metabolism found that these bacteria are able to utilize iron and nitrogen from their surroundings and recycle scarce nutrients to meet their metabolic needs. (Another member of the same group, Halomonas titanicae, is so named because it is consuming the iron superstructure of the Titanic.)

Perhaps most importantly, the team found that the microbes living in the deep sandstone deposits of the Illinois Basin were capable of metabolizing aromatic compounds, a common component of petroleum.

“This means that these indigenous microbes would have the adaptive edge if hydrocarbon migration eventually does occur,” Fouke said.

A better understanding of the microbial life of the subterranean world will “enhance our ability to explore for and recover oil and gas, and to make more environmentally sound choices for subsurface gas storage,” he said.

Study uncovers new evidence for assessing tsunami risk from very large volcanic island landslides

A core is extracted from the seabed. -  Russell Wynn
A core is extracted from the seabed. – Russell Wynn

The risk posed by tsunami waves generated by Canary Island landslides may need to be re-evaluated, according to researchers at the National Oceanography Centre. Their findings suggest that these landslides result in smaller tsunami waves than previously thought by some authors, because of the processes involved.

The researchers used the geological record from deep marine sediment cores to build a history of regional landslide activity over the last 1.5 million years. They found that each large-scale landslide event released material into the ocean in stages, rather than simultaneously as previously thought.

The findings – reported recently in the scientific journal Geochemistry Geophysics Geosystems – can be used to inform risk assessment from landslide-generated tsunamis in the area, as well as mitigation strategies to defend human populations and infrastructure against these natural hazards. The study also concluded that volcanic activity could be a pre-condition to major landslide events in the region.

The main factor influencing the amplitude of a landslide-generated tsunami is the volume of material sliding into the ocean. Previous efforts, which have assessed landslide volumes, have assumed that the entire landslide volume breaks away and enters the ocean as a single block. Such studies – and subsequent media coverage – have suggested an event could generate a ‘megatsunami’ so big that it would travel across the Atlantic Ocean and devastate the east coast of the US, as well as parts of southern England.

The recent findings shed doubt on this theory. Instead of a single block failure, the landslides in the past have occurred in multiple stages, reducing the volumes entering the sea, and thereby producing smaller tsunami waves. Lead author Dr James Hunt explains: “If you drop a block of soap into a bath full of water, it makes a relatively big splash. But if you break it up into smaller pieces and drop it in bit by bit, the ripples in the bath water are smaller.”

The scientists were able to identify this mechanism from the deposits of underwater sediment flows called turbidity currents, which form as the landslide mixes with surrounding seawater. Their deposits, known as ‘turbidites’, were collected from an area of the seafloor hundreds of miles away from the islands. Turbidites provide a record of landslide history because they form from the material that slides down the island slopes into the ocean, breaks up and eventually settles on this flatter, deeper part of the seafloor.

However, the scientists could not assume that multistage failure necessarily results in less devastating tsunamis – the stages need to occur with enough time in between so that the resulting waves do not compound each other. “If you drop the smaller pieces of soap in one by one but in very quick succession, you can still generate a large wave,” says Dr Hunt.

Between the layers of sand deposited by the landslides, the team found mud, providing evidence that the stages of failure occurred some time apart. This is because mud particles are so fine that they most likely take weeks to settle out in the ocean, and even longer to form a layer that would be resistant enough to withstand a layer of sand moving over the top of it.

While the authors suggest that the tsunamis were not as big as originally thought, they state that tsunamis are a threat that the UK should be taking seriously. The Natural Environment Research Council (NERC) is investing in a major programme looking at the risk of tsunamis from Arctic landslides as part of the Arctic Research Programme, of which NOC is the lead collaborator. The EU have also just funded a £6 million FP7 project called ASTARTE, looking at tsunami risk and resilience on the European North Atlantic and Mediterranean coasts, of which NOC is a partner.

The current study was funded by NERC, through a NOC studentship.

Researchers quantify toxic ocean conditions during major extinction 93.9 million years ago

Oxygen in the atmosphere and ocean rose dramatically about 600 million years ago, coinciding with the first proliferation of animal life.Since then, numerous short lived biotic events – typically marked by significant climatic perturbations – took place when oxygen concentrations in the ocean dipped episodically.

The most studied and extensive of these events occurred 93.9 million years ago. By looking at the chemistry of rocks deposited during that time period, specifically coupled carbon and sulfur isotope data, a research team led by University of California, Riverside biogeochemists reports that oxygen-free and hydrogen sulfide-rich waters extended across roughly five percent of the global ocean during this major climatic perturbation – far more than the modern ocean’s 0.1 percent but much less than previous estimates for this event.

The research suggests that previous estimates of oxygen-free and hydrogen sulfide-rich conditions, or “euxinia,” were too high. Nevertheless, the limited and localized euxinia were still sufficiently widespread to have dramatic effect on the entire ocean’s chemistry and thus biological activity.

“These conditions must have impacted nutrient availability in the ocean and ultimately the spatial and temporal distribution of marine life,” said team member Jeremy D. Owens, a former UC Riverside graduate student, who is now a postdoctoral scientist at the Woods Hole Oceanographic Institution. “Under low-oxygen environments, many biologically important metals and other nutrients are removed from seawater and deposited in the sediments on the seafloor, making them less available for life to flourish.”

“What makes this discovery particularly noteworthy is that we mapped out a landscape of bioessential elements in the ocean that was far more perturbed than we expected, and the impacts on life were big,” said Timothy W. Lyons, a professor of biogeochemistry at UCR, Owens’s former advisor and the principal investigator on the research project.

Study results appear online this week in the Proceedings of the National Academy of Sciences.

Across the event 93.9 million years ago, a major biological extinction in the marine realm has already been documented. Also associated with this event are high levels of carbon dioxide in the atmosphere, which are linked to elevated ocean and atmospheric temperatures. Associated consequences include likely enhanced global rainfall and weathering of the continents, which further shifted the chemistry of the ocean.

“Our work shows that even though only a small portion of the ocean contained toxic and metal-scavenging hydrogen sulfide, it was sufficiently large so that changes to the ocean’s chemistry and biology were likely profound,” Owens said. “What this says is that only portions of the ocean need to contain sulfide to greatly impact biota.”

For their analysis, the researchers collected seafloor mud samples, now rock, from multiple localities in England and Italy. They then performed chemical extraction on the samples to analyze the sulfur isotope compositions in order to estimate the chemistry of the global ocean.

According to the researchers, the importance of their study is elevated by the large amount of previous work on the same interval and thus the extensive availability of supporting data and samples. Yet despite all this past research, the team was able to make a fundamental discovery about the global conditions in the ancient ocean and their impacts on life.

“Today, we are facing rising carbon dioxide contents in the atmosphere through human activities, and the amount of oxygen in the ocean may drop correspondingly in the face of rising seawater temperatures,” Lyons said. “Oxygen is less soluble in warmer water, and there are already suggestions of such decreases. In the face of these concerns, our findings from the warm, oxygen-poor ancient ocean may be a warning shot about yet another possible perturbation to marine ecology in the future.”

Mountaintop mining pollution has distinct chemical signatures

Three elements commonly found at elevated levels in an Appalachian river polluted by runoff from mountaintop coal mining have distinctive chemistries that can be traced back to their source, according to a Duke University-led study.

The distinctive chemistries of sulfur, carbon and strontium provide scientists with new, more accurate ways to track pollution from mountaintop mining sites and to distinguish it from contamination from other sources.

“Essentially, we found that these elements have unique isotopic fingerprints, meaning we can use them as diagnostic tools to quantify mountaintop mining’s relative contribution to contamination in a watershed,” said Avner Vengosh, professor of geochemistry and water quality at Duke’s Nicholas School of the Environment.

The newly identified tracers will be especially useful in watersheds with more than one source of potential contamination, he said. “Because they allow us to distinguish if contaminants are coming from natural sources, fracking and shale gas development, coal mining, coal ash disposal, or other causes.”

Vengosh and his team’s findings were published today in the online edition of the peer-reviewed journal Environmental Science & Technology.

The researchers measured the chemical and isotopic compositions of water samples collected monthly from 23 locations along West Virginia’s Upper Mud River and its tributaries between May and December 2012.

They found that the isotopic signatures of sulfur (in sulfate), carbon (in dissolved inorganic carbon) and strontium from water samples collected from tributaries adjacent to mountaintop mining sites are distinguishable from those collected from unaffected upstream waters. They also found that the strontium isotope ratio is a sensitive tracer for selenium contamination, one of the major pollutants of mountaintop mining.

In mountaintop mining, companies use explosives and heavy machinery to clear away surface rocks and extract shallow deposits of high-quality coal. The companies typically dispose of the waste rock in adjacent valleys, where they bury existing headwater streams.

Previous studies by the Duke team and others have shown that runoff from these “valley fills” contains elevated levels of salts and selenium, a known fish toxin. The contamination can persist and accumulate in downstream waters for decades after active mining stops and the fills are reclaimed.

By conducting tests that simulated the natural leaching of contaminants from local rocks, Vengosh and his team were able to characterize the chemistry of the different geological formations that end up as waste rock in these fills. They found significant differences in strontium isotope ratios and selenium concentrations in streams flowing from reclaimed valley fills versus those flowing from active fills.

“This helps us further pinpoint the source of contamination by linking it directly to the type of rocks in the valley fills,” Vengosh said.

The Upper Mud River flows through sparsely populated areas of southern West Virginia as a headwater stream. For about 10 kilometers, the river passes through the Hobet 21 surface mining complex, which has been active since the 1970s and is among the largest in the Appalachian coalfields.

‘Highway from hell’ fueled Costa Rican volcano

Volcanologist Philipp Ruprecht analyzed crystals formed as Irazú's magma cooled to establish how fast it traveled. -  Kim Martineau
Volcanologist Philipp Ruprecht analyzed crystals formed as Irazú’s magma cooled to establish how fast it traveled. – Kim Martineau

If some volcanoes operate on geologic timescales, Costa Rica’s Irazú had something of a short fuse. In a new study in the journal Nature, scientists suggest that the 1960s eruption of Costa Rica’s largest stratovolcano was triggered by magma rising from the mantle over a few short months, rather than thousands of years or more, as many scientists have thought. The study is the latest to suggest that deep, hot magma can set off an eruption fairly quickly, potentially providing an extra tool for detecting an oncoming volcanic disaster.

“If we had had seismic instruments in the area at the time we could have seen these deep magmas coming,” said the study’s lead author, Philipp Ruprecht, a volcanologist at Columbia University’s Lamont-Doherty Earth Observatory. “We could have had an early warning of months, instead of days or weeks.”

Towering more than 10,000 feet and covering almost 200 square miles, Irazú erupts about every 20 years or less, with varying degrees of damage. When it awakened in 1963, it erupted for two years, killing at least 20 people and burying hundreds of homes in mud and ash. Its last eruption, in 1994, did little damage.

Irazú sits on the Pacific Ring of Fire, where oceanic crust is slowly sinking beneath the continents, producing some of earth’s most spectacular fireworks. Conventional wisdom holds that the mantle magma feeding those eruptions rises and lingers for long periods of time in a mixing chamber several miles below the volcano. But ash from Irazú’s prolonged explosion is the latest to suggest that some magma may travel directly from the upper mantle, covering more than 20 miles in a few months.

“There has to be a conduit from the mantle to the magma chamber,” said study co-author Terry Plank, a geochemist at Lamont-Doherty. “We like to call it the highway from hell.”

Their evidence comes from crystals of the mineral olivine separated from the ashes of Irazú’s 1963-1965 eruption, collected on a 2010 expedition to the volcano. As magma rising from the mantle cools, it forms crystals that preserve the conditions in which they formed. Unexpectedly, Irazú’s crystals revealed spikes of nickel, a trace element found in the mantle. The spikes told the researchers that some of Irazú’s erupted magma was so fresh the nickel had not had a chance to diffuse.

“The study provides one more piece of evidence that it’s possible to get magma from the mantle to the surface in very short order,” said John Pallister, who heads the U.S. Geological Survey (USGS) Volcano Disaster Assistance Program in Vancouver, Wash. “It tells us there’s a potentially shorter time span we need to worry about.”

Deep, fast-rising magma has been linked to other big events. In 1991, Mount Pinatubo in the Philippines spewed so much gas and ash into the atmosphere that it cooled Earth’s climate. In the weeks before the eruption, seismographs recorded hundreds of deep earthquakes that USGS geologist Randall White later attributed to magma rising from the mantle-crust boundary. In 2010, a chain of eruptions at Iceland’s Eyjafjallajökull volcano that caused widespread flight cancellations also indicated that some magma was coming from down deep. Small earthquakes set off by the eruptions suggested that the magma in Eyjafjallajökull’s last two explosions originated 12 miles and 15 miles below the surface, according to a 2012 study by University of Cambridge researcher Jon Tarasewicz in Geophysical Research Letters.

Volcanoes give off many warning signs before a blow-up. Their cones bulge with magma. They vent carbon dioxide and sulfur into the air, and throw off enough heat that satellites can detect their changing temperature. Below ground, tremors and other rumblings can be detected by seismographs. When Indonesia’s Mount Merapi roared to life in late October 2010, officials led a mass evacuation later credited with saving as many as 20,000 lives.

Still, the forecasting of volcanic eruptions is not an exact science. Even if more seismographs could be placed along the flanks of volcanoes to detect deep earthquakes, it is unclear if scientists would be able to translate the rumblings into a projected eruption date. Most problematically, many apparent warning signs do not lead to an eruption, putting officials in a bind over whether to evacuate nearby residents.

“[Several months] leaves a lot of room for error,” said Erik Klemetti, a volcanologist at Denison University who writes the “Eruptions” blog for Wired magazine. “In volcanic hazards you have very few shots to get people to leave.”

Scientists may be able to narrow the window by continuing to look for patterns between eruptions and the earthquakes that precede them. The Nature study also provides a real-world constraint for modeling how fast magma travels to the surface.

“If this interpretation is correct, you start having a speed limit that your models of magma transport have to catch,” said Tom Sisson, a USGS volcanologist based at Menlo Park, Calif.

Olivine minerals with nickel spikes similar to Irazú’s have been found in the ashes of arc volcanoes in Mexico, Siberia and the Cascades of the U.S. Pacific Northwest, said Lamont geochemist Susanne Straub, whose ideas inspired the study. “It’s clearly not a local phenomenon,” she said. The researchers are currently analyzing crystals from past volcanic eruptions in Alaska’s Aleutian Islands, Chile and Tonga, but are unsure how many will bear Irazú’s fast-rising magma signature. “Some may be capable of producing highways from hell and some may not,” said Ruprecht.

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.