First detailed underwater survey of huge volcanic flank collapse deposits

This is an aerial view of the Soufriere Hills volcano on the island of Montserrat in the Lesser Antilles. The photograph was shows one of the volcanic domes that grew and then collapsed into the sea since the volcano became active in 1995. However, there have been far bigger collapse events in the distant past that involve the entire volcanic edifice. -  NOC
This is an aerial view of the Soufriere Hills volcano on the island of Montserrat in the Lesser Antilles. The photograph was shows one of the volcanic domes that grew and then collapsed into the sea since the volcano became active in 1995. However, there have been far bigger collapse events in the distant past that involve the entire volcanic edifice. – NOC

A scientific team led by Dr Peter Talling of the UK’s National Oceanography Centre (NOC) is currently aboard the Royal Research Ship James Cook to map extremely large landslide deposits offshore from an active volcano on Montserrat in the Lesser Antilles.

The volcano has been erupting episodically since 1995, with the last major eruption and volcanic dome collapse occurring in February 2010. Previous eruptions on the island have included the largest volcanic dome collapses ever documented. These eruptions were monitored on land, and marine surveys showed what happens when the hot volcanic flows enter the ocean.

Thousands of years ago, far larger collapses of the entire volcanic edifice occurred sending huge landslides into the ocean to the east and south of the island. Some of these landslides involved over five cubic kilometers of material and traveled underwater for tens of kilometers. They were much larger than even the largest of the volcanic dome collapses since 1995 and probably generated tsunamis, whose magnitude is uncertain.

“We plan to produce the first detailed survey of this type of volcanic flank collapse deposit,” said Dr Talling: “For the first time, we will image flank collapse deposits by collecting three-dimensional seismic reflection data, which will show how huge avalanches were emplaced.”

The researchers wish to learn if landslides from the volcano that are violently emplaced on the seafloor can trigger even larger-scale failure of the underlying seafloor sediment. They have already successfully collected sonar images that show huge blocks of material scattered across the seafloor, forming a halo around the base of the island. Some of these blocks are over 40 meters high and 400 meters long. Sonar images also show streaks of material deposited underwater during the February 2010 eruption.

In the next two weeks, the team will finish mapping the flank collapse deposits using seismic reflection data. This seafloor mapping will provide survey data for an ambitious International Ocean Drilling Program (IODP) proposal to drill into and recover landslide material. This will help date the landslides and show whether they are associated with particular eruptions or other changes in volcano behavior.

The people of Montserrat live in the north of the island, the southern part of the island containing the active volcano having been evacuated, including the old capital city of Plymouth, which is now mainly buried and destroyed.

The scientists are in close contact with Montserrat Volcano Observatory and hope that their work will help to understand the longer-term history of the volcano and help predict future hazards. They especially wish to understand the frequency and triggers of these huge landslides and the size and frequency of tsunamis that they could potentially generate.

“The way in which huge volcanic edifices collapse into the sea should become clearer during the next few days,” said Talling: “These collapse events represent some of the most fascinating and potentially hazardous events around island volcanoes.”

Ironically, the recent eruption of Eyjafjallajökull in Iceland threatened the study of the Montserrat volcano by nearly stopping the researchers from flying out to the Caribbean in time to join the vessel.

The research represents a collaborative project between the National Oceanography Centre (NOC), the University of Southampton’s School of Ocean and Earth Sciences, IFM Geomar in Kiel and the Institute de Physique du Globe de Paris (IPGP).

Special paper provides synthesized view of the dynamic Ordovician Earth

GSA Special Paper 466 synthesizes the expertise of scientists from the United States, Canada, Sweden, Denmark, China, Russia and Argentina to provide readers with detailed and up-to-date data, diagrams, and discussion on what Earth must have been like between 444 and 488 million years ago. -  Geological Society of America
GSA Special Paper 466 synthesizes the expertise of scientists from the United States, Canada, Sweden, Denmark, China, Russia and Argentina to provide readers with detailed and up-to-date data, diagrams, and discussion on what Earth must have been like between 444 and 488 million years ago. – Geological Society of America

Spanning 44-million years, the Ordovician is a significant chapter in Earth’s history. A time of dynamic change among and on the major continents (in a far different configuration than what we know now), the Ordovician was characterized by wide oceans, warm near the surface but with cold, deep basins; explosive volcanism; two major positive isotope carbon excursions; both the great Ordovician biodiversification event and the Hirnantian mass extinction; glaciation; and long-term greenhouse conditions.

Editors Stanley C. Finney of California State University at Long Beach and William B.N. Berry of the University of California at Berkeley have synthesized the expertise of scientists from the United States, Canada, Sweden, Denmark, China, Russia, and Argentina to provide readers with detailed and up-to-date data, diagrams, and discussion on what Earth must have been like between 444 and 488 million years ago.

Ordovician rocks, including shales, richly fossiliferous carbonates, and glacial and glacio-marine siliciclastic sediments, are widespread on most continents. The recent finalization of a modern chronostratigraphic classification of the Ordovician system now facilitates high-resolution correlations, allowing for integrated, multidisciplinary research. The diverse chapters in this new GSA Special Paper address orogenesis, paleogeography, climate modeling, sedimentation, biodiversity, and isotopic excursions (including a focus on the “less conspicuous” Late Ordovician Guttenberg isotope carbon excursion); together they promote an integrated view of the Ordovician Earth system.

Millions awarded for earthquake monitoring

More than $7 million in cooperative agreements will be awarded for earthquake monitoring by the U.S Geological Survey in 2010. This funding will contribute to the development and operation of the USGS Advanced National Seismic System (ANSS).

“Earthquake monitoring is absolutely critical to providing fast information to emergency-response personnel in areas affected by earthquakes, so by building and repairing those monitoring systems, these cooperative agreements literally save lives and property,” said Secretary of the Interior Ken Salazar.

As part of the National Earthquake Hazards Reduction Program, the ANSS provides continuous, real-time monitoring of earthquake activity and collects critical information about how earthquake shaking affects buildings and structures. Funds are also being provided for the operation of geodetic monitoring networks, which detect minute changes in the earth’s crust caused by faulting in earthquake-prone regions.

“The ultimate goal of earthquake monitoring is to save lives, ensure public safety, and reduce economic losses,” said Bill Leith, a USGS scientist and coordinator of the ANSS. “Rapid, accurate information about earthquake location and shaking has greatly improved the response time of emergency managers following an earthquake.”

Nationwide, 39 states are considered to be at moderate-to-high risk of a damaging earthquake. Although the frequency of earthquakes on the West Coast is higher than other areas of the United States, many eastern cities are also at risk, including St. Louis, Mo., Memphis, Tenn., New York, N.Y., Boston, Mass., and many others.

Institutions receiving funding for monitoring through seismic and geodetic networks include the California Institute of Technology; University of Washington; University of Utah; University of California, Berkeley; University of Memphis; University of Alaska, Fairbanks; University of Nevada, Reno; Columbia University; St. Louis University; Boston College; University of California, San Diego; University of South Carolina; Montana Bureau of Mines and Geology (Montana Tech of the University of Montana); University of Oregon; Central Washington University; University of Colorado; and San Francisco State University.

World’s largest polar science conference to take place in Oslo

There’s still time for media to register for the largest polar science meeting ever held. The conference will celebrate and publish early results from the International Polar Year 2007-2008 (IPY).

WHAT: International Polar Year Oslo Science Conference

WHEN: June 8 to 12, 2010

WHERE: Norway Trade Fairs, Lillestrom, Norway (15 minutes by train from Oslo)

MEDIA REGISTRATION: http://www.ipy-osc.no/article/2010/1265207747.88

The conference is the first opportunity after completion of IPY field activities for direct interaction among participants from all 160 IPY science cluster projects. The meeting provides an excellent opportunity for journalists to keep up to date with the latest in global climate research – some of which will provide the scientific foundation for COP16 in Mexico in November, and the next IPCC report.

REGISTER NOW:
To get full access to the conference activities and content, media will need to obtain a participant card. Media representatives are eligible for waived registration fees. Eligibility for press registration must be substantiated through submission of the Press Registration Form with the required documentation.

For more information on the procedure for press registration:
http://www.ipy-osc.no/article/2010/1265207747.88

Included in the participant card is free transport between the city and the venue, a free lunch at the venue, and access to social events. To receive your card on arrival, register before June 1.

HIGHLIGHTS:

  • A focus on climate research

  • More than 2,000 participants from 60 nations
  • 1200 oral presentations in almost 40 sessions
  • Over 500 early career scientists from around the world
  • Results from science education and outreach efforts

WHY YOU SHOULD CONSIDER THIS CONFERENCE:

IPY was an intensive, internationally coordinated scientific research campaign in the Arctic and the Antarctic sponsored by the International Council for Science (ICSU) and the World Meteorological Organization (WMO). In two action-packed years, IPY researchers observed exciting new phenomena, made fundamental scientific discoveries, developed new methods and tools, advanced interdisciplinary and international links in polar science and, most importantly, gained new understanding of the role of the Polar Regions in the total Earth system.

The IPY Oslo Science Conference will emphasize the breadth and global impact of polar research during IPY. It will highlight the extraordinary interdisciplinary and multinational efforts in research and in communication of research to the public. Participants will present early scientific results from all the IPY themes, particularly in the urgent areas of:

  1. Linkages between polar regions and global systems

  2. Past, present and future changes in polar regions
  3. Polar ecosystems and biodiversity
  4. Health and well-being of northern people and communities
  5. New frontiers and new directions in polar research
  6. Polar science education, outreach and communication

To view the conference program:
http://elsevier.conference-services.net/programme.asp?conferenceID=1976

ONSITE MEDIA SERVICES:

  • Serviced press centre available to all registered journalists

  • Full time photographer will provide pool photos from the event
  • High resolution photos available daily on conference website
  • Conference photographer can be commissioned for portraits of interviewees, etc.
  • Photographers available for demanding tasks at the rate of about USD $1000 per full day
  • Morning media briefings held to present the key activities of the day
  • Plenary sessions and other activities streamed live on the web
  • Afternoon PolarEXCHANGE sessions organized as moderated talk shows to explore scientific highlights

Plenary speakers will be urged to make themselves available for questions from the press immediately after their lectures. Suitable backdrops and the necessary lights will be provided at these improvised press conferences.

Melting sea ice major cause of warming in Arctic, new study reveals

Melting sea ice has been shown to be a major cause of warming in the Arctic according to a University of Melbourne, Australia study.

Findings published in Nature today reveal the rapid melting of sea ice has dramatically increased the levels of warming in the region in the last two decades.

Lead author Dr James Screen of the School of Earth Sciences at the University of Melbourne says the increased Arctic warming was due to a positive feedback between sea ice melting and atmospheric warming.

“The sea ice acts like a shiny lid on the Arctic Ocean. When it is heated, it reflects most of the incoming sunlight back into space. When the sea ice melts, more heat is absorbed by the water. The warmer water then heats the atmosphere above it. “

“What we found is this feedback system has warmed the atmosphere at a faster rate than it would otherwise,” he says.

Using the latest observational data from the European Centre for Medium-Range Weather Forecasting, Dr Screen was able to uncover a distinctive pattern of warming, highly consistent with the loss of sea ice.

“In the study, we investigated at what level in the atmosphere the warming was occurring. What stood out was how highly concentrated the warming was in the lower atmosphere than anywhere else. I was then able to make the link between the warming pattern and the melting of the sea ice.”

The findings question previous thought that warmer air transported from lower latitudes toward the pole, or changes in cloud cover, are the primary causes of enhanced Arctic warming.

Dr Screen says prior to this latest data set being available there was a lot of contrasting information and inconclusive data.

“This current data has provided a fuller picture of what is happening in the region,” he says.

Over the past 20 years the Arctic has experienced the fastest warming of any region on the planet. Researchers around the globe have been trying to find out why.

Researchers say warming has been partly caused by increasing human greenhouse gas emissions. At the same time, the Arctic sea ice has been declining dramatically. In summer 2007 the Arctic had the lowest sea ice cover on record. Since then levels have recovered a little but the long-term trend is still one of decreasing ice.

Professor Ian Simmonds, of the University’s School of Earth Sciences and coauthor on the paper says the findings are significant.

“It was previously thought that loss of sea ice could cause further warming. Now we have confirmation this is already happening.”

Through the looking glass: Scientists peer into Antarctica’s past to see

The JOIDES Resolution encounters rough seas during the transit to Antarctica. - Credit: John Beck, IODP/TAMU
The JOIDES Resolution encounters rough seas during the transit to Antarctica. – Credit: John Beck, IODP/TAMU

New results from a research expedition in Antarctic waters may provide critical clues to understanding one of the most dramatic periods of climate change in Earth’s history.

Some 53 million years ago, Antarctica was a warm, sub-tropical environment. During this same period, known as the “greenhouse” or “hothouse” world, atmospheric carbon dioxide levels exceeded those of today by ten times.

Then suddenly, Antarctica’s lush environment transitioned into its modern icy realm.

Newly acquired climate records tell a tale of this long-ago time. The records were recovered from Antarctica, preserved in sediment cores retrieved during the Integrated Ocean Drilling Program (IODP) Wilkes Land Glacial History Expedition from Jan. 4 – March 8, 2010.

Wilkes Land is the region of Antarctica that lies due south of Australia, and is believed to be one of the most climate-sensitive regions of the polar continent.

In only 400,000 years–a mere blink of an eye in geologic time–concentrations of atmospheric carbon dioxide there decreased. Global temperatures dropped. Ice sheets developed. Antarctica became ice-bound.

How did this change happen so abruptly, and how stable can we expect ice sheets to be in the future?

To answer these questions, an international team of scientists participating in the Wilkes Land Glacial History Expedition spent two months aboard the scientific research vessel JOIDES Resolution, drilling geological samples from the seafloor off the coast of Antarctica.

“The new cores offer an unprecedented ability to decipher the history of glaciation in Antarctica,” says Jamie Allen, program director in the National Science Foundation (NSF)’s Division of Ocean Sciences, which co-funds IODP.

“The climate record they preserve is immensely valuable, especially for testing how well current global climate models reproduce past history.”

Despite braving icebergs, near gale-force winds, snow and fog, Wilkes Land Expedition scientists recovered approximately 2,000 meters (more than one mile) of sediment core.

“These sediments are essential to our research because they preserve the history of the Antarctic ice sheet,” says Carlota Escutia of the Research Council of Spain CSIC-University of Granada, who led the expedition, along with co-chief scientist Henk Brinkhuis of Utrecht University in the Netherlands.

“We can read these sediments like a history book,” Brinkhuis says. “And this book goes back 53 million years, giving us an unprecedented record of how ice sheets form and interact with changes in the climate and the ocean.”

The new core samples collected during the expedition are unique because they provide the world’s first direct record of waxing and waning of ice in this region of Antarctica.

Combined, the cores tell a story of Antarctica’s transition from an ice-free, warm, greenhouse world to a cold, dry, “icehouse” world.

Sediments and microfossils preserved within the cores document the onset of cooling and the development of the first Antarctic glaciers, as well as the growth and recession of Antarctica’s ice sheets.

Cores from one site resemble tree rings–alternating bands of light and dark sediment preserve seasonal variability of the last deglaciation, which began some 10,000 years ago.

Understanding the behavior of Antarctica’s ice sheets plays an important role in our ability to build effective global climate models, say scientists, which are used to predict future climate.

“These models rely on constraints imposed by data from the field,” the expedition co-chief scientists point out.

“Measurements of parameters such as age, temperature, and carbon dioxide concentration increase the accuracy of these models. The more we can constrain the models, the better they’ll perform–and the better we can predict ice sheet behavior.”

What’s next?

The science team now embarks on a multi-year process of on-shore analyses to further investigate the Wilkes Land cores.

Age-dating and chemistry studies, among other analyses, are expected to resolve questions about changes in Antarctica’s climate over short timescales (50-20,000 years).

Data collected from the Wilkes Land Expedition will complement previous research from drilling operations conducted elsewhere in the Antarctic over the last 40 years.

The research will provide important age constraints for models of Antarctic ice sheet development and evolution, forming the basis for models of future ice sheet behavior and polar climate change.

IODP is an international marine research program dedicated to advancing scientific understanding of the Earth through drilling, coring, and monitoring the sub-seafloor.

Scientists probe Earth’s core

Researchers David Eaton and Catrina Alexandrakis from the University of Calgary used measurements of distant earthquakes to learn more about the Earth's core. -  Meghan Sired, University of Calgary
Researchers David Eaton and Catrina Alexandrakis from the University of Calgary used measurements of distant earthquakes to learn more about the Earth’s core. – Meghan Sired, University of Calgary

We know more about distant galaxies than we do about the interior of our own planet. However, by observing distant earthquakes, researchers at the University of Calgary have revealed new clues about the top of the Earth’s core in a paper published in the May edition of the journal Physics of the Earth and Planetary Interiors.

Knowledge of the composition and state in this zone is key to unraveling the source of the Earth’s magnetic field and the formation of our planet.

“Some scientists have proposed a region of sediment accumulation at the top of the core, or even distinct liquid layers, but this study shows that the outer core is, in fact, well mixed,” says professor Dave Eaton, co-author of the paper. “This inaccessible region is composed of molten iron, nickel and other as-yet unknown lighter elements such as silicon, sulfur, carbon or oxygen.”

To help try and determine the materials that make up the Earth’s core, which is 2,891 km below the surface, Eaton and co-author Catrina Alexandrakis, University of Calgary PhD student, measured the seismic wave speed (speed of sound) at the top of Earth’s core.

“Observation of distant earthquakes is one of the few tools that scientists have to investigate deep parts of the Earth,” says Alexandrakis. “This isn’t the first time earthquake data has been used, but our research method is the most definitive to date.”

The researchers’ method is based on ‘listening’ to earthquakes on the other side of the planet using an approach that is akin to hearing a conversation across a whispering gallery, such as those in the domes of some large cathedrals.

Using a novel digital processing approach, they analyzed faint signals, produced by 44 earthquakes, and were able to measure the sound speed at the top of Earth’s core with unprecedented accuracy.

Their results will help to guide research efforts at laboratories where core composition is studied by simulating extreme pressure and temperature conditions that exist in the Earth’s core.

Locating tsunami warning buoys

Australian researchers describe a mathematical model in the International Journal of Operational Research that can find the ten optimal sites at which tsunami detection buoys and sea-level monitors should be installed. The model could save time and money in the installation of a detection system as well as providing warning for the maximum number of people should a potentially devastating tsunami occur again in the Indian Ocean.

A magnitude 9.3 shook the sea floor off the coast of Aceh, in northern Sumatra, Indonesia, on 26 December 2004. The quake led to an overwhelming tsunami with waves as high as 10.5 m travelling at up to 8 m per second. Within two hours the tsunami had reached Colombo, in Sri Lanka and then the east coast of India. Almost eight hours later, fishing villages on the east coast of Africa in Kenya and Somalia felt its impact. There was no warning for the people affected and almost a quarter of a million lives were lost across eleven nations fringing the Indian Ocean.

In 2005, the first steps to install a tsunami warning system in the Indian Ocean were being taken, with plans to deploy 24 tsunami detection buoys. The author of the study, Layna Groen and Lindsay Botten of the Department of Mathematical Sciences, at the University of Technology, and Katerina Blazek previously at Sinclair Knight Merz, in Sydney, NSW, Australia, suggest that their model has significant implications for the construction and maintenance of the tsunami warning system in the Indian Ocean.

The Intergovernmental Oceanographic Commission (IOC) of the United Nations Educational, Scientific and Cultural Organisation (UNESCO) planned the establishment of the Indian Ocean Tsunami Warning and Mitigation System (IOTWS). The detection/alert system is the crucial component consisting of seismic detectors, sea-level monitors and deep-sea pressure sensors attached to deep ocean buoys.

Groen and colleagues have focused on the latter two components as being critical to an adequate warning system. They point out that relatively few detection buoys are yet in place and a number of sea-level monitoring stations are still to be constructed. Their study, which uses the well-known modeling tool “Mathematica”, should help the IOTWS decision makers in determining where the remaining buoys should be placed.

The team’s analysis supports the positioning of the 40 proposed buoys, but points out that just 1o buoys would be adequate for warning the maximum number of people. They add that the same mathematical modeling approach could be applied to tsunami detection in the Atlantic Ocean, the Mediterranean, Caribbean, and Black Seas.

“The imperative for this is made clear in the UNESCO Intergovernmental Oceanographic Committee estimate that ‘by the year 2025, three-quarters of the world’s population will be living in coastal areas’, and ‘The expanded tsunami network that the Intergovernmental Oceanographic Commission of UNESCO is coordinating is just the first step in building a global tsunami warning system designed to monitor oceans and seas everywhere’.”