New online atlas shows how climate change will affect distribution patterns of forests

Today, territory and species conservation managers need to rely on data and empirical methods on which to base their protection policies. Within the context of Global Change, the maps offered can be useful to evaluate possible changes in the distribution of forests in the future, which could lead to an in depth study of mitigation and/or adaptation tools needed to face these changes.

Until now, a few maps had been drawn for specific woody plants or for partial areas of the peninsula. The Suitability Atlas of Woody Plants however offers a global view of the Iberian Peninsula. The series of maps were created to determine the degree of suitability to climate and/or topographic conditions of the forests’ main woody plants. With the help of these maps one can verify, in an area of 200 meters, the topo-climatic suitability of the Iberian Peninsula. In addition, these values can be consulted for the current climatic scenario (1950-1998) and for future projections proposed by one of the foremost research centers dedicated to climate change, the Hadley Centre, located in Exeter, UK.

The Atlas combines advanced methodologies and technologies such as Geographic Information Systems, multivariate statistics and interoperable geoportals to offer both rigorous cartographic standards and information that can be consulted by the general public.

The Atlas was developed by a group of researchers from the UAB Department of Animal Biology, Plant Biology and Ecology, in collaboration with the Centre for Ecological Research and Forestry Applications (CREAF), under the framework of the R&D&I National Plan.

Main features of the Atlas

  • Completeness: covering almost all woody species found in forests
  • Quality initial data: both the Digital Climate Atlas of the Iberian Peninsula (ACDPI) and the third National Forest Inventory are cartography databases with high spatial resolution and with proven data quality.
  • Detailed resolution: 200 m spatial resolution
  • Objectivity: numerical quality (known level of error) calculated and documented for each map.
  • Interoperability: format in which maps can be viewed allows users to contrast information with other map databases
  • Accessibility: maps can be consulted online in GIS format without the need of additional installations.

First results

Researchers have already obtained the first scientific results with the help of Atlas data. They were able to verify that many species could be affected by the reduction in suitability in the regions they currently inhabit. They detected a tendency in forests to migrate towards higher altitudes and more northern latitudes. In this sense, mountain ranges such as the Pyrenees are seen as important protection areas of biodiversity within the context of Climate Change.

Nevertheless, not all species react the same when suffering the consequences of climate change. Species such as aleppo pine, stone pine, or holm oak are more resistant and may even occupy larger areas in the future. In contrast, species such as scots pine or beech are more affected by rising temperatures and longer dry periods and therefore the space they occupy may begin to decrease.

At these moments researchers are studying the total forest surface which could be lost or substituted by scrubs, as well as interactions between forest species when their area of distribution is modified. The fact that forest surfaces are decreasing is of great relevance, since this represents a reduction in CO2 consumption, an increase in the risk of land erosion and modifications in water cycles.

Extending the life of oil reserves

A research team led by the University of Bristol has used STFC’s ISIS Neutron Source to come up with a new way to treat carbon dioxide (CO2), so that it can be used in efficient and environmentally friendly methods for extracting oil. These new CO2 soluble additives can also be used to reduce the environmental damage caused by every day industrial processes such as food processing and the manufacture of electronics. The results of this work are published in the journal Langmuir.

The researchers have developed a soap-like additive for CO2 that turns it into a viable solvent for commercial-scale enhanced oil recovery to increase the amount of crude oil that can be extracted from oil fields.

“Carbon dioxide is useful in enhanced oil recovery as it is able to flow through the pores in the rock much more easily than water,” said Professor Julian Eastoe from the University of Bristol. “The additive, a surfactant, will help thicken the carbon dioxide, which is vital for this process, allowing it to flow through the rock more efficiently. There is also a useful side effect of our ability to use CO2 in this way, as in the future the process will take carbon dioxide generated by industrial activity from the atmosphere and lock it deep underground. Getting longer life out of existing oil reserves will also give more time for research into replacements into non-carbon energy sources such as solar or hydrogen.”

Minister for Science and Universities David Willetts said: “This shows what science can do for the environment. It’s why the Government has protected the science budget. In particular it shows how financing core science facilities can lead to many different projects with valuable applications.”

Liquid CO2 is increasingly being used industrially to replace common petrochemical solvents because it requires less processing and it can be easily recycled. The difficulty has been that in order to operate effectively as a solvent, carbon dioxide needs additives, many of which are in themselves, damaging to the environment. This new development by an international team including scientists from Bristol University led by Professor Julian Eastoe, from the University of Pittsburgh led by Professor Bob Enick and ISIS scientists Dr Sarah Rogers and Dr Richard Heenan provides a solution. The project has been funded by the UK Engineering and Physical Sciences Research Council (EPSRC) and the US Department of Energy to explore using high pressure CO2 to extract residual oil retained in the pores of rock.

“The quest to find a chemical capable of modifying the properties of CO2 to make it suitable for widespread use as a solvent in enhanced oil recovery has been long,” said Professor Bob Enick. “Previous advances have involved surfactants containing fluorine, which although highly soluble in CO2, are very environmentally damaging. The new additive, surfactant TC14, contains no fluorine at all and is a harmless hydrocarbon.”

CO2 offers an efficient, cheap, non-toxic, non-flammable and environmentally responsible alternative to conventional petrochemical solvents. Even water as a solvent for example, comes with its own set of problems; after being used to flush out oil from rocks it then requires cleaning before it can be used again, whereas liquid CO2 can be re-used immediately.

The paper published in the Langmuir is the first to come from Sans2d, one of seven new neutron instruments built at the ISIS second target station, a £145 million expansion to the facility completed last year. It is also one of the first to be published using data collected at the new target station.

The new additive, surfactant TC14 enables small pockets to form in the liquid CO2 called reverse micelles causing the liquid to thicken. Neutron scattering at ISIS allowed the structure of the reverse micelles to be studied in the CO2 as they formed under high pressure. The neutron instruments giving this molecular level viewpoint are often described as ‘super-microscopes’.

“Beams of neutrons are able to penetrate deep inside samples giving unique information about the location and arrangement of the micelles at a molecular level,” said ISIS scientist Dr Sarah Rogers.

“By altering the pressure in a specially constructed experimental cell, dissolved material can easily be separated and removed leaving the carbon dioxide for the next use. It would be difficult to look at this system using any other technique as the CO2 needs to be kept under high pressure. Only under the scrutiny of neutron beams can you fully reveal its actions and properties.”

“Experiments on Sans2d are particularly fast and accurate in comparison to some older neutron scattering instruments. This development of neutron instrument technology is part of what makes ISIS a world leading science facility,” said Professor Eastoe.

SCEC’s ‘M8′ earthquake simulation breaks computational records, promises better quake models

This image shows detail from the M8 simulation. To view a video simulation go to http://www.scivee.tv/node/21179. -  Southern California Earthquake Center
This image shows detail from the M8 simulation. To view a video simulation go to http://www.scivee.tv/node/21179. – Southern California Earthquake Center

A multi-disciplinary team of researchers has presented the world’s most advanced earthquake shaking simulation at the Supercomputing 2010 (SC10) conference held this week in New Orleans. The research was selected as a finalist for the Gordon Bell prize, awarded at the annual conference for outstanding achievement in high-performance computing applications.

The “M8″ simulation represents how a magnitude 8.0 earthquake on the southern San Andreas Fault will shake a larger area, in greater detail, than previously possible. Perhaps most importantly, the development of the M8 simulation advances the state-of-the-art in terms of the speed and efficiency at which such calculations can be performed.

The Southern California Earthquake Center (SCEC) at the University of Southern California (USC) was the lead coordinator in the project. San Diego Supercomputer Center (SDSC) researchers provided the high-performance computing and scientific visualization expertise for the simulation. Scientific details of the earthquake were developed by scientists at San Diego State University (SDSU). Ohio State University (OSU) researchers were also part of the collaborative effort to improve the efficiency of the software involved.

While this specific earthquake has a low probability of occurrence, the improvements in technology required to produce this simulation will now allow scientists to simulate other more likely earthquakes scenarios in much less time than previously required. Because such simulations are the most important and widespread applications of high performance computing for seismic hazard estimation currently in use, the SCEC team has been focused on optimizing the technologies and codes needed to create them.

The M8 simulation was funded through a number of National Science Foundation (NSF) grants and it was performed using supercomputer resources including NSF’s Kraken supercomputer at National Institute for Computational Science (NICS) and the Department of Energy (DOE) Jaguar supercomputer at the National Center for Computational Science . The SCEC M8 simulation represents the latest in earthquake science and in computations at the petascale level, which refers to supercomputers capable of more than one quadrillion floating point operations (calculations) per second.

“Petascale simulations such as this one are needed to understand the rupture and wave dynamics of the largest earthquakes, at shaking frequencies required to engineer safe structures,” said Thomas Jordan, director of SCEC and Principal Investigator for the project. Previous simulations were useful only for modeling how tall structures will behave in earthquakes, but the new simulation can be used to understand how a broader range of buildings will respond.

“The scientific results of this massive simulation are very interesting, and its level of detail has allowed us to observe things that we were not able to see in the past,” said Kim Olsen, professor of geological sciences at SDSU, and lead seismologist of the study. .

However, given the massive number of calculations required, only the most advanced supercomputers are capable of producing such simulations in a reasonable time period. “This M8 simulation represents a milestone calculation, a breakthrough in seismology both in terms of computational size and scalability,” said Yifeng Cui, a computational scientist at SDSC. “It’s also the largest and most detailed simulation of a major earthquake ever performed in terms of floating point operations, and opens up new territory for earthquake science and engineering with the goal of reducing the potential for loss of life and property.”

Specifically, the M8 simulation is the largest in terms duration of the shaking modeled (six minutes) and the geographical area covered – a rectangular volume approximately 500 miles (810km) long by 250 miles (405 km) wide, by 50 miles (85km) deep. The team’s latest research also set a new record in the number of computer processor cores used, with 223,074 cores sustaining performance of 220 trillion calculations per second for 24 hours on the Jaguar Cray XT5 supercomputer at the Oak Ridge National Laboratory (ORNL) in Tennessee.

“We have come a long way in just six years, doubling the seismic frequencies modeled by our simulations every two to three years, from 0.5 Hertz (or cycles per second) in the TeraShake simulations, to 1.0 Hertz in the ShakeOut simulations, and now to 2.0 Hertz in this latest project,” said Phil Maechling, SCEC’s associate director for Information Technology.

In terms of earthquake science, these simulations can be used to study issues of how earthquake waves travel through structures in the earth’s crust and to improve three-dimensional models of such structures.

“Based on our calculations, we are finding that deep sedimentary basins, such as those in the Los Angeles area, are getting larger shaking than are predicted by the standard methods,” Jordan said. “By improving the predictions, making them more realistic, we can help engineers make new buildings safer.” The simulations are also useful in developing better seismic hazard policies and for improving scenarios used in emergency planning.

Panama Canal, Panama City at risk of large earthquake, says new research

Satellite image showing location of Panama canal.
Satellite image showing location of Panama canal.

New data suggest that the Limon and Pedro Miguel faults in Central Panama have ruptured both independently and in unison over the past 1400 years, indicating a significant seismic risk for Panama City and the Panama Canal, according to research published today by the Bulletin of the Seismological Society of America (BSSA).

The Panama Canal is undergoing expansion to allow for greater traffic of larger ships, scheduled for completion by 2014. As part of a seismic hazard characterization for the Panama Canal Authority (ACP) expansion project, Rockwell, et al., studied the geologic and geomorphic expression of the Pedro Miguel, Limon, and related faults, followed by an in-depth study into their earthquake and displacement history, critical factors in the design of the Panama Canal new locks and associated structures.

“The Pedro Miguel fault actually runs between the existing Pacific locks – the Pedro Miguel and Miraflores locks – and last ruptured in a large earthquake in 1621,” said lead author Thomas K. Rockwell, professor of geology at San Diego State University. “That earthquake resulted in nearly 10 feet of displacement where the fault crosses the canal, and a similar amount of offset of the historical Camino de Cruces, the old Spanish cobblestone road that was used to haul South American gold across the isthmus. Another such earthquake today could have dramatic effects.”

The Republic of Panama sits atop two colliding tectonic plates — Central and South America — and is internally deforming at a significant rate. The Pedro Miguel, Limon and related faults comprise a zone that extends from the southern flank of the Sierra Maestra in north central Panama southward for at least 40 km (about 25 miles) crossing the Panama Canal between the Miraflores and Pedro Miguel Locks, and extending southward offshore into the Gulf of Panama.

Paleoseismic work by Rockwell, et al., demonstrates that both the Limon and Pedro Miguel faults are seismically active, having a relatively short recurrence rate for large earthquakes, with displacements in the range of 1.5 to 3 meters (4.9 to 9.8 feet). The oldest event on the Pedro Miguel fault is estimated at 455 AD and is older than any of the events recorded for the Limon fault. However, the penultimate Pedro Miguel event and the third Limon fault event identified in this study have very similar ages at about 700 AD and may represent rupture of the entire onshore zone.

The apparent ability for these two distinct faults to fail in unison has important implications for Panama Canal. While no fault passes through or beneath any critical structures, the area and structures would be subject to significant shaking. The authors note that the close proximity of Panama City to this active fault zone, and the lack of consideration of earthquake loads in structural design codes, puts this area at high seismic risk, particularly before current buildings can be replaced with stronger, more earthquake-resistant construction.

Appalachia in the limelight

A new memoir from the Geological Society of America, 'From Rodinia to Pangea: The Lithotectonic Record of the Appalachian,' contains 36 original papers reporting the results of research performed throughout nearly the entire length and breadth of the Appalachian region, including all major provinces and geographical areas. -  The Geological Society of America
A new memoir from the Geological Society of America, ‘From Rodinia to Pangea: The Lithotectonic Record of the Appalachian,’ contains 36 original papers reporting the results of research performed throughout nearly the entire length and breadth of the Appalachian region, including all major provinces and geographical areas. – The Geological Society of America

The Appalachians have served as a springboard for innovative geologic thought for more than 170 years. A new volume from The Geological Society of America contains 36 original papers reporting the results of research performed throughout nearly the entire length and breadth of the Appalachian region, including all major provinces and geographical areas.

Memoir 206, From Rodinia to Pangea: The Lithotectonic Record of the Appalachian Region, grew out of GSA’s 2007 Northeastern Section meeting in Durham, New Hampshire, and commemorates the (near) fortieth anniversary of the publication of the classic Studies of Appalachian Geology volumes that appeared just prior to the application of plate tectonic concepts to the region.

Contributions in structural evolution, sedimentation, stratigraphy, magmatic processes, metamorphism, tectonics, and terrane accretion illustrate the wide range of ongoing research in the area and collectively serve to mark the considerable progress in scientific thought that has occurred during the past four decades.

Research highlights 3D perspectives, sequence stratigraphic techniques, and improved geochemical databases for the exploration of regional-scale modeling.

10 years of Soufriere Hills Volcano research published

Top: This is a photo of the growing Soufriere Hills Volcano lava dome taken May 31, 2003. Bottom: This is a photo from the same location taken Aug. 12, 2003. Approximately 120,000 cubic meters of the dome collapsed in a 24-hour period. -  Montserrat Volcano Observatory/British Geological Survey
Top: This is a photo of the growing Soufriere Hills Volcano lava dome taken May 31, 2003. Bottom: This is a photo from the same location taken Aug. 12, 2003. Approximately 120,000 cubic meters of the dome collapsed in a 24-hour period. – Montserrat Volcano Observatory/British Geological Survey

The Soufriere Hills Volcano on Montserrat erupted in 1995, and an international team of researchers has studied this volcano from land and sea since then to understand the workings of andesite volcanos more completely.

“To the extent that the Soufriere Hills Volcano is typical of andesitic dome building volcanoes, results from this research can be expected to apply more generally,” said Barry Voight, professor emeritus of geosciences, Penn State.

Voight and R. S. J. Sparks, the Channing Wills professor of geology, Bristol University, guest edited and introduced a special issue of Geophysical Research Letters that covers the past ten years of research in the CALIPSO (Caribbean Andesite Lava Island Precision Seismo-geodetic Observatory) and SEA-CALIPSO (Seismic Experiment with Airgun) projects. The U. S. National Science Foundation, U. K. Natural Environmental Research Council, British Geological Survey and Discovery Channel funded these projects.

CALIPSO is a volcano monitoring system installed in late 2002 and early 2003 to monitor magma activity of the volcano. It consists of an array of specialized instruments located in four strategically placed, 650-foot-deep bore holes along with surface and shallow-hole instrumentation. Reports on research from this project look at surface deformation, magma activity, explosive dynamics of the volcano and the magma system. The papers cover four different explosive episodes and volcano mechanics.

SEA-CALIPSO obtained three-dimensional images of the structure of the island of Montserrat and of the volcano’s center. It was an active-source seismic experiment to study the Earth’s crust beneath the island and the volcano and was under the umbrella of the CALIPSO project.

“This multinational experiment with participation from the U.S., UK, New Zealand, Trinidad and Montserrat generated high resolution images of the island, its volcanic edifices and adjacent crust,” said Voight. “This project should advance our understanding of how crust evolves in arc systems, magma is stored and transported and how volcanic processes proceed.”

SEA-CALIPSO used seismic tomography, seismic reflection/refraction imaging and offshore seismic profiling to view the deep structure of the volcano. Evaluation of the speed at which seismic waves pass beneath and through the island can provide information on the structure of the crust and the magma chambers beneath the volcano.

The research on both projects was also supported by the Government of Montserrat, Seismic Research Center of the University of West Indies.

Rare earth elements in US not so rare

Approximately 13 million metric tons of rare earth elements (REE) exist within known deposits in the United States, according to the first-ever nationwide estimate of these elements by the U.S. Geological Survey.

This estimate of domestic rare earth deposits is part of a larger report that includes a review of global sources for REE, information on known deposits that might provide domestic sources of REE in the future, and geologic information crucial for studies of the availability of REE to U.S. industry.

The report describes significant deposits of REE in 14 states, with the largest known REE deposits at Mountain Pass, Calif.; Bokan Mountain, Alaska; and the Bear Lodge Mountains, Wyo. The Mountain Pass mine produced REE until it closed in 2002. Additional states with known REE deposits include Colorado, Florida, Georgia, Idaho, Illinois, Missouri, Nebraska, New Mexico, New York, North Carolina, and South Carolina.

“This is the first detailed assessment of rare earth elements for the entire nation, describing deposits throughout the United States,” commented USGS Director Marcia McNutt, Ph.D. “It will be very important, both to policy-makers and industry, and it reinforces the value of our efforts to maintain accurate, independent information on our nation’s natural resources. Although many of these deposits have yet to be proven, at recent domestic consumption rates of about 10,000 metric tons annually, the US deposits have the potential to meet our needs for years to come.”

REE are a group of 16 metallic elements with similar properties and structures that are essential in the manufacture of a diverse and expanding array of high-technology applications. Despite their name, they are relatively common within the earth’s crust, but because of their geochemical properties, they are not often found in economically exploitable concentrations.

Hard-rock deposits yield the most economically exploitable concentrations of REE. USGS researchers also analyzed two other types of REE deposits: placer and phosphorite deposits. Placer deposits are alluvial formations of sandy sediments, which often contain concentrations of heavy, dense minerals, some containing REE. Phosphorite deposits, which mostly occur in the southeastern U.S., contain large amounts of phosphate-bearing minerals. These phosphates can yield yttrium and lanthanum, which are also REE.

Ninety-six percent of REE produced globally now comes from China. New REE mines are being developed in Australia, and projects exploring the feasibility of economically developing additional REE deposits are under way in the United States, Australia, and Canada; successful completion of these projects could help meet increasing demand for REE, the report said.

REE are important ingredients in high-strength magnets, metal alloys for batteries and light-weight structures, and phosphors. These are essential components for many current and emerging alternative energy technologies, such as electric vehicles, photo-voltaic cells, energy-efficient lighting, and wind power. REEs are also critical for a number of key defense applications.

This report is part of a larger, Department of Defense-funded study of how the United States, and the Department of Defense in particular, use REE, as well as the status and security of domestic and global supply chains. In addition, the USGS National Minerals Information Center maintains statistics on global mineral production, trade, and resources that include rare earth elements.

A history of Earth’s convulsions

New Geological Society of America Special Paper 471, Ancient Earthquakes, includes a selection of cases which illustrate ways that the archaeological record is being used in earthquake studies. The volume will be of interest to the broad community of earth scientists, seismologists, historians, and archaeologists active in and around archaeological sites threatened by seismic hazards throughout the world. -  The Geological Society of America
New Geological Society of America Special Paper 471, Ancient Earthquakes, includes a selection of cases which illustrate ways that the archaeological record is being used in earthquake studies. The volume will be of interest to the broad community of earth scientists, seismologists, historians, and archaeologists active in and around archaeological sites threatened by seismic hazards throughout the world. – The Geological Society of America

Ancient earthquakes are pre-instrumental earthquakes that can only be identified through indirect evidence in the archaeological (archaeoseismology) and geological (palaeoseismology) record. New GSA Special Paper 471 includes a selection of cases which illustrate ways that the archaeological record is being used in earthquake studies. Ancient Earthquakes will be of interest to the broad community of earth scientists, seismologists, historians, and archaeologists active in and around archaeological sites threatened by seismic hazards throughout the world.

The volume frames the International Geoscience Programme IGCP 567, “Earthquake Archaeology: Archaeoseismology along the Alpine-Himalayan Seismic Zone.” The first series of papers focuses on the relationship between human prehistory and tectonically active environments, and the wide range of societal responses to historically known earthquakes. Papers primarily concern archaeoseismology. They show the diversity of disciplines and approaches involved, and each one’s potential to contribute to a better understanding of earthquake history.

The second series of papers focuses on societal impacts and discusses issues in political, social and economic contexts. These works further review whether earthquakes have had a negative effect on society.

“We hope this volume offers a taste of the complexity with which archaeoseismologists are confronted,” say the editors.

Months of geologic unrest signaled reawakening of Icelandic volcano

Months of volcanic restlessness preceded the eruptions this spring of Icelandic volcano Eyjafjallajökull, providing insight into what roused it from centuries of slumber.

An international team of researchers analyzed geophysical changes in the long-dormant volcano leading up to its eruptions in March and April 2010 that suggest that magma flowing beneath the volcano may have triggered its reawakening. Their study is published in the Nov. 18 issue of the journal Nature.

“Several months of unrest preceded the eruptions, with magma moving around downstairs in the plumbing and making noise in the form of earthquakes,” says study co-author Kurt Feigl, a professor of geosciences at the University of Wisconsin-Madison. “By monitoring volcanoes, we can understand the processes that drive them to erupt.”

With funding from a RAPID grant from the U.S. National Science Foundation, Feigl and collaborators from Iceland, Sweden, and the Netherlands used a combination of satellite imaging and GPS surveying to watch the volcano’s edifice as it deformed. They found that the volcano swelled for 11 weeks before it began to erupt in March 2010 from one flank.

“If you watch a volcano for decades, you can tell when it’s getting restless,” Feigl says.

In late summer 2009, a subtle shift at a GPS station on Eyjafjallajökull’s flank prompted the study’s lead author, Freysteinn Sigmundsson, and his colleagues to begin monitoring the mountain more closely. Then, in early January 2010, the rate of deformation and the number of earthquakes began to increase. As the deformation and seismic unrest continued, the researchers installed more GPS stations near the mountain. Just a few weeks later, the instruments detected more rapid inflation, indicating that magma was moving upwards through the “plumbing” inside the volcano.

By the time the volcano began to erupt on March 20, the volcano’s flanks had expanded by more than six inches as magma flowed from deep within the Earth into shallow chambers underneath the mountain.

Surprisingly, the rapid deformation stopped as soon as the eruption began. In many cases, volcanoes deflate as magma flows out of shallow chambers during an eruption. Eyjafjallajökull, however, maintained basically the same inflated shape through mid-April, when the first eruption ended.

After a two-day pause, the volcano began to erupt again on April 22. This time, the lava broke out through a new conduit under the ice on the summit of the mountain, causing an explosive reaction as water flashed to steam and gas escaped from bubbles in the magma. The resulting “ash” plume rose high into the atmosphere, disrupting air traffic over Europe for weeks and stranding millions of travelers.

Why did Eyjafjallajökull erupt when it did? The geologic processes that trigger an actual eruption are not yet well understood, says Feigl. “We’re still trying to figure out what wakes up a volcano.”

To begin to answer this question, the scientists suggest that a magmatic intrusion deep within the volcano may have triggered the eruption, but this hypothesis remains to be tested at other volcanoes.

They are also studying the structures inside the volcano, such as magma chambers and intrusive conduits, by extracting information from the sensors installed around Eyjafjallajökull.

“The explosiveness of the eruption depends on the type of magma, and the type of magma depends on the depth of its source,” Feigl says. “We’re a long way from being able to predict eruptions, but if we can visualize the magma as it moves upward inside the volcano, then we’ll improve our understanding of the processes driving volcanic activity.”

Newly discovered drumlin field provides answers about glaciation and climate

This is the edge of the Múlajökull glacier on Iceland. The ridges between the lakes are drumlins. -  Ívar Örn Benediktsson
This is the edge of the Múlajökull glacier on Iceland. The ridges between the lakes are drumlins. – Ívar Örn Benediktsson

The landform known as a drumlin, created when the ice advanced during the Ice Age, can also be produced by today’s glaciers. This discovery, made by researchers from the University of Gothenburg, Sweden, has just been published in the scientific journal Geology.

Drumlins generally consist of an accumulation of glacial debris – till – and are found in areas that were covered by ice sheet. As the ice advanced, it moved rocks, gravel and sand and created tear-shaped raised ridges running parallel with the movement of the ice.

“Until now, scientists have been divided on how drumlins were created,” says Mark Johnson from the Department of Earth Sciences at the University of Gothenburg. “Because they are formed under the ice, it’s not an observable process. Drumlins are common almost everywhere the Ice Age ice sheets existed, but they’re almost unknown with modern-day glaciers. Now, though, we’ve found a new drumlin field by the Múlajökull glacier on Iceland. It’s quite unique.”

The melting of glaciers reveals drumlins

The melting of glaciers as a result of climate change has helped the researchers to study this geological phenomenon. The drumlin discovery on Iceland has presented unique opportunities to study their structure.

“One of the drumlins we found was sliced through by erosion. This gave us an opportunity to study it layer by layer, and it was clear that it had been built up only recently. In other words, the glacier has not just retreated to reveal old drumlins, but is continuing to create new ones.”

There are currently multiple theories about the origins of drumlins. The Gothenburg researchers’ discovery shows that they can form within two kilometers of the edge of the ice.

“A surging glacier can move 100 meters a day, as opposed to the more normal 100 meters a year. If we can link drumlins to fast-moving glaciers, this would mean that the ice sheet advanced much more quickly than scientists currently believe.”

Can effect climate research


The link between drumlins and rapid ice movements is important for climate research. When modeling climate change, we need to know how high and how cold a glacier was in order to understand the last Ice Age. A glacier that moves quickly will not be as thick. This discovery could therefore affect how scientists approach climate modeling.

Solving the riddle of the drumlin is a longstanding dream for Mark Johnson:

“We discovered the drumlin field while flying in towards the edge of the glacier to do a completely different study. It was the most exciting thing I’ve been involved in during my research. All geologists know about drumlins, and when I began to study geology in Wisconsin in the 1980s, many people would come there to study the drumlins in the area. Coming up with a theory for how they formed was a big question even then.”

The discovery of the new drumlin field was made by Mark Johnson from the Department of Earth Sciences at the University of Gothenburg in collaboration with researchers from Iceland, Norway and the UK.