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.”

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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.

Aiming to improve the air quality in underground mines

Reducing diesel particulate matter emitted by the diesel powered vehicles used for underground mine work is the aim of researchers from Monash University. -  Monash University
Reducing diesel particulate matter emitted by the diesel powered vehicles used for underground mine work is the aim of researchers from Monash University. – Monash University

Reducing diesel particulate matter (DPM) exposure to miners in underground coalmines will be a step closer to reality with the awarding of a research grant to engineers from Monash University.

The $275,000 grant from the Australian Coal Association Research Programme (ACARP) goes to a multi-disciplinary team from the Maintenance Technology Institute (MTI), the Laboratory for Turbulence Research in Aerospace and Combustion (LTRAC) and the Australian Pulp and Paper Institute (APPI).

The grant will allow them to collaborate with leading industry original equipment manufacturers and mine site personnel as part of a broader long-term strategy to minimise DPM emissions in the mining industry.

Joint project leader Associate Professor Damon Honnery said it was important to find a way to reduce miners exposure to DPM which is both effective and cost efficient.

“DPM has recently been classified as a Group 1 carcinogen by the World Health Organisation, and is a significant problem for operators of underground coalmines,” Associate Professor Honnery said.

“Diesel powered vehicles are widely used for underground mine work and are generally fitted with diesel particulate filters (DPFs) to reduce particulate emissions which have very limited service life – typically around one or two shifts – resulting in excessive costs and ineffective control of DPM.”

The new project will complement an earlier ACARP project by the team that focussed on improving the service life of DPFs used in underground coalmines, which found reconditioned filters could be reused up to five times without compromising filter integrity or DPM filtration efficiency.

Fellow Project leader Dr Daya Dayawansa said while the earlier results offer a viable short-term solution to the DPM problem, a medium-term solution requires the careful examination and possible redesign of the entire exhaust conditioning system, in combination with improved diesel particulate filters.

Ultimately, the researchers believe that many diesel engines used in underground mining could be replaced by electric motors, despite the stringent regulations relating to electric systems in the potentially explosive underground atmosphere.

“While filter use will continue to reduce the impact of DPM emission in underground mines, the only truly effective long term solution is to remove the source from the mines altogether. Working with our partners, we hope to achieve this through the development of electric powered vehicles,” Dr Dayawansa said.

Acid mine drainage reduces radioactivity in fracking waste

Much of the naturally occurring radioactivity in fracking wastewater might be removed by blending it with another wastewater from acid mine drainage, according to a Duke University-led study.

“Fracking wastewater and acid mine drainage each pose well-documented environmental and public health risks. But in laboratory tests, we found that by blending them in the right proportions we can bind some of the fracking contaminants into solids that can be removed before the water is discharged back into streams and rivers,” said Avner Vengosh, professor of geochemistry and water quality at Duke’s Nicholas School of the Environment.

“This could be an effective way to treat Marcellus Shale hydraulic fracturing wastewater, while providing a beneficial use for acid mine drainage that currently is contaminating waterways in much of the northeastern United States,” Vengosh said. “It’s a win-win for the industry and the environment.”

Blending fracking wastewater with acid mine drainage also could help reduce the depletion of local freshwater resources by giving drillers a source of usable recycled water for the hydraulic fracturing process, he added.

“Scarcity of fresh water in dry regions or during periods of drought can severely limit shale gas development in many areas of the United States and in other regions of the world where fracking is about to begin,” Vengosh said. “Using acid mine drainage or other sources of recycled or marginal water may help solve this problem and prevent freshwater depletion.”

The peer-reviewed study was published in late December 2013 in the journal Environmental Science & Technology.

In hydraulic fracturing – or fracking, as it is sometimes called – millions of tons of water are injected at high pressure down wells to crack open shale deposits buried deep underground and extract natural gas trapped within the rock. Some of the water flows back up through the well, along with natural brines and the natural gas. This “flowback fluid” typically contains high levels of salts, naturally occurring radioactive materials such as radium, and metals such as barium and strontium.

A study last year by the Duke team showed that standard treatment processes only partially remove these potentially harmful contaminants from Marcellus Shale wastewater before it is discharged back into streams and waterways, causing radioactivity to accumulate in stream sediments near the disposal site.

Acid mine drainage flows out of abandoned coal mines into many streams in the Appalachian Basin. It can be highly toxic to animals, plants and humans, and affects the quality of hundreds of waterways in Pennsylvania and West Virginia.

Because much of the current Marcellus shale gas development is taking place in regions where large amounts of historic coal mining occurred, some experts have suggested that acid mine drainage could be used to frack shale gas wells in place of fresh water.

To test that hypothesis, Vengosh and his team blended different mixtures of Marcellus Shale fracking wastewater and acid mine drainage, all of which were collected from sites in western Pennsylvania and provided to the scientists by the industry.

After 48 hours, the scientists examined the chemical and radiological contents of 26 different mixtures. Geochemical modeling was used to simulate the chemical and physical reactions that had occurred after the blending; the results of the modeling were then verified using x-ray diffraction and by measuring the radioactivity of the newly formed solids.

“Our analysis suggested that several ions, including sulfate, iron, barium and strontium, as well as between 60 and 100 percent of the radium, had precipitated within the first 10 hours into newly formed solids composed mainly of strontium barite,” Vengosh said. These radioactive solids could be removed from the mixtures and safely disposed of at licensed hazardous-waste facilities, he said. The overall salinity of the blended fluids was also reduced, making the treated water suitable for re-use at fracking sites.

“The next step is to test this in the field. While our laboratory tests show that is it technically possible to generate recycled, treated water suitable for hydraulic fracturing, field-scale tests are still necessary to confirm its feasibility under operational conditions,” Vengosh said.

Mine landslide triggered quakes

The April 10, 2013, landslide at Rio Tinto-Kennecott Utah Copper's Bingham Canyon mine contains enough debris to bury New York City's Central Park 66 feet deep, according to a new University of Utah study. The slide happened in the form of two rock avalanches 95 minutes apart. The first rock avalanche included grayer bedrock material seen around the margins of the lower half of the slide. The second rock avalanche is orange in color, both from bedrock and from waste rock from mining. The new study found the landslide triggered 16 small quakes. Such triggering has not been noted previously. The slide likely was the largest nonvolcanic landslide in North America's modern history. -  Kennecott Utah Copper.
The April 10, 2013, landslide at Rio Tinto-Kennecott Utah Copper’s Bingham Canyon mine contains enough debris to bury New York City’s Central Park 66 feet deep, according to a new University of Utah study. The slide happened in the form of two rock avalanches 95 minutes apart. The first rock avalanche included grayer bedrock material seen around the margins of the lower half of the slide. The second rock avalanche is orange in color, both from bedrock and from waste rock from mining. The new study found the landslide triggered 16 small quakes. Such triggering has not been noted previously. The slide likely was the largest nonvolcanic landslide in North America’s modern history. – Kennecott Utah Copper.

Last year’s gigantic landslide at a Utah copper mine probably was the biggest nonvolcanic slide in North America’s modern history, and included two rock avalanches that happened 90 minutes apart and surprisingly triggered 16 small earthquakes, University of Utah scientists discovered.

The landslide – which moved at an average of almost 70 mph and reached estimated speeds of at least 100 mph – left a deposit so large it “would cover New York’s Central Park with about 20 meters (66 feet) of debris,” the researchers report in the January 2014 cover study in the Geological Society of America magazine GSA Today.

While earthquakes regularly trigger landslides, the gigantic landslide the night of April 10, 2013, is the first known to have triggered quakes. The slide occurred in the form of two huge rock avalanches at 9:30 p.m. and 11:05 p.m. MDT at Rio Tinto-Kennecott Utah Copper’s open-pit Bingham Canyon Mine, 20 miles southwest of downtown Salt Lake City. Each rock avalanche lasted about 90 seconds.

While the slides were not quakes, they were measured by seismic scales as having magnitudes up to 5.1 and 4.9, respectively. The subsequent real quakes were smaller.

Kennecott officials closely monitor movements in the 107-year-old mine – which produces 25 percent of the copper used in the United States – and they recognized signs of increasing instability in the months before the slide, closing and removing a visitor center on the south edge of the 2.8-mile-wide, 3,182-foot-deep open pit, which the company claims is the world’s largest manmade excavation.

Landslides – including those at open-pit mines but excluding quake-triggered slides – killed more than 32,000 people during 2004-2011, the researchers say. But no one was hurt or died in the Bingham Canyon slide. The slide damaged or destroyed 14 haul trucks and three shovels and closed the mine’s main access ramp until November.

“This is really a geotechnical monitoring success story,” says the new study’s first author, Kris Pankow, associate director of the University of Utah Seismograph Stations and a research associate professor of geology and geophysics. “No one was killed, and yet now we have this rich dataset to learn more about landslides.”

There have been much bigger human-caused landslides on other continents, and much bigger prehistoric slides in North America, including one about five times larger than Bingham Canyon some 8,000 years ago at the mouth of Utah’s Zion Canyon.

But the Bingham Canyon Mine slide “is probably the largest nonvolcanic landslide in modern North American history,” said study co-author Jeff Moore, an assistant professor of geology and geophysics at the University of Utah.

There have been numerous larger, mostly prehistoric slides – some hundreds of times larger. Even the landslide portion of the 1980 Mount St. Helens eruption was 57 times larger than the Bingham Canyon slide.

News reports initially put the landslide cost at close to $1 billion, but that may end up lower because Kennecott has gotten the mine back in operation faster than expected.

Until now, the most expensive U.S. landslide was the 1983 Thistle slide in Utah, which cost an estimated $460 million to $940 million because the town of Thistle was abandoned, train tracks and highways were relocated and a drainage tunnel built.

Pankow and Moore conducted the study with several colleagues from the university’s College of Mines and Earth Sciences: J. Mark Hale, an information specialist at the Seismograph Stations; Keith Koper, director of the Seismograph Stations; Tex Kubacki, a graduate student in mining engineering; Katherine Whidden, a research seismologist; and Michael K. McCarter, professor of mining engineering.

The study was funded by state of Utah support of the University of Utah Seismograph Stations and by the U.S. Geological Survey.

Rockslides Measured up to 5.1 and 4.9 in Magnitude, but Felt Smaller

The University of Utah researchers say the Bingham Canyon slide was among the best-recorded in history, making it a treasure trove of data for studying slides.

Kennecott has estimated the landslide weighed 165 million tons. The new study estimated the slide came from a volume of rock roughly 55 million cubic meters (1.9 billion cubic feet). Rock in a landslide breaks up and expands, so Moore estimated the landslide deposit had a volume of 65 million cubic meters (2.3 billion cubic feet).

Moore calculated that not only would bury Central Park 66 feet deep, but also is equivalent to the amount of material in 21 of Egypt’s great pyramids of Giza.

The landslide’s two rock avalanches were not earthquakes but, like mine collapses and nuclear explosions, they were recorded on seismographs and had magnitudes that were calculated on three different scales:

  • The first slide at 9:30 p.m. MDT measured 5.1 in surface-wave magnitude, 2.5 in local or Richter magnitude, and 4.2 in duration or “coda” magnitude.

  • The second slide at 11:05 p.m. MDT measured 4.9 in surface-wave magnitude, 2.4 in Richter magnitude and 3.5 in coda magnitude.

Pankow says the larger magnitudes more accurately reflect the energy released by the rock avalanches, but the smaller Richter magnitudes better reflect what people felt – or didn’t feel, since the Seismograph Stations didn’t receive any such reports. That’s because the larger surface-wave magnitudes record low-frequency energy, while Richter and coda magnitudes are based on high-frequency seismic waves that people usually feel during real quakes.

So in terms of ground movements people might feel, the rock avalanches “felt like 2.5,” Pankow says. “If this was a normal tectonic earthquake of magnitude 5, all three magnitude scales would give us similar answers.”

The slides were detected throughout the Utah seismic network, including its most distant station some 250 miles south on the Utah-Arizona border, Pankow says.

The Landslide Triggered 16 Tremors

The second rock avalanche was followed immediately by a real earthquake measuring 2.5 in Richter magnitude and 3.0 in coda magnitude, then three smaller quakes – all less than one-half mile below the bottom of the mine pit.

The Utah researchers sped up recorded seismic data by 30 times to create an audio file in which the second part of the slide is heard as a deep rumbling, followed by sharp gunshot-like bangs from three of the subsequent quakes.

Later analysis revealed another 12 tiny quakes – measuring from 0.5 to minus 0.8 Richter magnitude. (A minus 1 magnitude has one-tenth the power of a hand grenade.) Six of these tiny tremors occurred between the two parts of the landslide, five happened during the two days after the slide, and one was detected 10 days later, on April 20. No quakes were detected during the 10 days before the double landslide.

“We don’t know of any case until now where landslides have been shown to trigger earthquakes,” Moore says. “It’s quite commonly the reverse.”

A Long, Fast Landslide Runout

The landslide, from top to bottom, fell 2,790 vertical feet, but its runout – the distance the slide traveled – was almost 10,072 feet, or just less than two miles.

“It was a bedrock landslide that had a characteristically fast and long runout – much longer than we would see for smaller rockfalls and rockslides,” Moore says.

While no one was present to measure the speed, rock avalanches typically move about 70 mph to 110 mph, while the fastest moved a quickly as 220 mph.

So at Bingham Canyon, “we can safely say the material was probably traveling at least 100 mph as it fell down the steepest part of the slope,” Moore says.

The researchers don’t know why the slide happened as two rock avalanches instead of one, but Moore says, “A huge volume like this can fail in one episode or in 10 episodes over hours.”

The Seismograph Stations also recorded infrasound waves from the landslide, which Pankow says are “sound waves traveling through the atmosphere that we don’t hear” because their frequencies are so low.

Both seismic and infrasound recordings detected differences between the landslide’s two rock avalanches. For example, the first avalanche had stronger peak energy at the end that was lacking in the second slide, Pankow says.

“We’d like to be able to use data like this to understand the physics of these large landslides,” Moore says.

The seismic and infrasound recordings suggest the two rock avalanches were similar in volume, but photos indicate the first slide contained more bedrock, while the second slide contained a higher proportion of mined waste rock – although both avalanches were predominantly bedrock.

Gold mining ravages Peru

The Carnegie Airborne Observatory flies over the Madre De Dios region of Peru, where vast deforested and polluted areas result from gold mining. -  Image courtesy Carnegie Airborne Observatory
The Carnegie Airborne Observatory flies over the Madre De Dios region of Peru, where vast deforested and polluted areas result from gold mining. – Image courtesy Carnegie Airborne Observatory

For the first time, researchers have been able to map the true extent of gold mining in the biologically diverse region of Madre De Dios in the Peruvian Amazon. The team combined field surveys with airborne mapping and high-resolution satellite monitoring to show that the geographic extent of mining has increased 400% from 1999 to 2012 and that the average annual rate of forest loss has tripled since the Great Recession of 2008. Until this study, thousands of small, clandestine mines that have boomed since the economic crisis have gone unmonitored. The research is published in the online early edition of the Proceedings of the National Academy of Sciences the week of October 28, 2013.

The team, led by Carnegie’s Greg Asner in close collaboration with officials from the Peruvian Ministry of Environment, used the Carnegie Landsat Analysis System-lite (CLASlite) to detect and map both large and small mining operations. CLASlite differs from other satellite mapping methods. It uses algorithms to detect changes to the forest in areas as small as 10 square meters, about 100 square feet, allowing scientists to find small-scale disturbances that cannot be detected by traditional satellite methods.

The team corroborated the satellite results with on-ground field surveys and Carnegie Airborne Observatory (CAO) data. The CAO uses Light Detection and Ranging (LiDAR), a technology that sweeps laser light across the vegetation canopy to image it in 3-D. It can determine the location of single standing trees at 3.5 feet (1.1 meter) resolution. This level of detail was used to assess how well CLASlite determined forest conditions in the mining areas. The CAO data were also used to evaluate the accuracy of the CLASlite maps along the edges of large mines, as well as the inaccessible small mines that are set back from roads and rivers to avoid detection. The field and CAO data confirmed up to 94% of the CLASlite mine detections.

Lead author Asner commented: “Our results reveal far more rainforest damage than previously reported by the government, NGOs, or other researchers. In all, we found that the rate of forest loss from gold mining accelerated from 5,350 acres (2,166 hectares) per year before 2008 to15,180 acres (6,145 hectares) each year after the 2008 global financial crisis that rocketed gold prices.”

In addition to wreaking direct havoc on tropical forests, gold mining releases sediment into rivers, with severe effects on aquatic life. Other recent work has shown that Perú’s gold mining has contributed to widespread mercury pollution affecting the entire food chain, including the food ingested by people throughout the region. Miners also hunt wild game, depleting the rainforest fauna around mining areas, and disrupting the ecological balance for centuries to come.

Co-author Ernesto Raez Luna, Senior Advisor to the Minister, Peruvian Ministry of the Environment, remarked: “Obtaining good information on illegal gold mining, to guide sound policy and enforcement decisions, has been particularly difficult so far. Finally, we have very detailed and accurate data that we can turn into government action. We are using this study to warn Peruvians on the terrible impact of illegal mining in one of the most important enclaves of biodiversity in the world, a place that we have vowed, as a nation, to protect for all humanity. Nobody should buy one gram of this jungle gold. The mining must be stopped.”

As of 2012, small illicit mines accounted for more than half of all mining operations in the region. Large mines of previous focus are heavy polluters but are taking on a subordinate role to thousands of small mines in degrading the tropical forest throughout the region. This trend highlights the importance of using this newer, high-resolution monitoring system for keeping tabs on this growing cause of forest loss.

Asner emphasized: “The gold rush in Madre de Dios, Perú, exceeds the combined effects of all other causes of forest loss in the region, including from logging, ranching and agriculture. This is really important because we’re talking about a global biodiversity hotspot. The region’s incredible flora and fauna is being lost to gold fever. “

Mining for heat

Underground mining is a sweaty job, and not just because of the hard work it takes to haul ore: Mining tunnels fill with heat naturally emitted from the surrounding rock. A group of researchers from McGill University in Canada has taken a systematic look at how such heat might be put to use once mines are closed. They calculate that each kilometer of a typical deep underground mine could produce 150 kW of heat, enough to warm 5 to 10 Canadian households during off-peak times.

A number of communities in Canada and Europe already use geothermal energy from abandoned mines. Noting these successful, site-specific applications, the McGill research team strove to develop a general model that could be used by engineers to predict the geothermal energy potential of other underground mines. In a paper accepted for publication in the American Institute of Physics’ Journal of Renewable and Sustainable Energy, the researchers analyze the heat flow through mine tunnels flooded with water. In such situations, hot water from within the mine can be pumped to the surface, the heat extracted, and the cool water returned to the ground. For the system to be sustainable, heat must not be removed more quickly than it can be replenished by the surrounding rock. The team’s model can be used to analyze the thermal behavior of a mine under different heat extraction scenarios.

“Abandoned mines demand costly perpetual monitoring and remediating. Geothermal use of the mine will offset these costs and help the mining industry to become more sustainable,” says Seyed Ali Ghoreishi Madiseh, lead author on the paper. The team estimates that up to one million Canadians could benefit from mine geothermal energy, with an even greater potential benefit for more densely populated countries such as Great Britain.