Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Deciphering the Mysteries of an Ancient Seafloor Goliath

12.04.2010
“Supervolcanoes” have been blamed for multiple mass extinctions in Earth’s history, but the cause of these massive eruptions remains poorly understood. To explore the origins of these seafloor giants, scientists drilled into a large, 145 million-year-old volcanic mountain chain lying underwater off the coast of Japan.

The eruptions of “supervolcanoes” on Earth’s surface have been blamed for causing mass extinctions, belching large amounts of gases and particles into the atmosphere, and re-paving the ocean floor. The result?

Loss of species, increased greenhouse gases in the atmosphere, and changes in ocean circulation. Despite their global impact, the origin and triggering mechanism of these eruptions remain poorly understood. New data collected during a recent Integrated Ocean Drilling Program (IODP) scientific research expedition in the Pacific Ocean may provide clues to unlocking this unsolved mystery in Earth’s geologic record.

In fall 2009, an international team of scientists participating in IODP Expedition 324 “Shatsky Rise Formation,” drilled five sites in the ocean floor to study the origin of the 145 million-year-old Shatsky Rise volcanic mountain chain. Located approximately 1500 kilometers (930 miles) east of Japan, Shatsky Rise measures roughly the size of California. This underwater mountain chain represents one of the largest supervolcanoes in the world: the top of Shatsky Rise lies three and a half kilometers (about two miles) below the sea surface, while its base plunges to nearly six kilometers (four miles) below the surface. Shatsky Rise is composed of layers of hardened lava, with individual lava flows that are up to 23 meters (75 feet) thick.

“Seafloor supervolcanoes are characterized by the eruption of enormous volumes of lava. Studying their formation is critical to understanding the processes of volcanism and the movement of material from the Earth’s interior to the surface,” remarked Dr. William Sager of Texas A&M University, who led the expedition together with co-chief scientist Dr. Takashi Sano of Japan’s National Museum of Nature and Science in Tokyo.

About a dozen supervolcanoes exist on Earth – some are found on land, while others lie at the bottom of the ocean. Those found on the seafloor are often referred to as “large oceanic plateaus.” Current scientific thinking suggests that these supervolcanoes were caused by eruptions occurring over a period of a few million years or less – a rapid pace in geologic time. Each of these supervolcanoes produced several million cubic kilometers of lava – about three hundred times the volume of all the Great Lakes combined – dwarfing the volume of lava produced by the biggest present-day volcanoes such as Hawaii.

Since the 1960s, geologists have debated the formation and origin of these large oceanic plateaus. The mystery lies in the origin of the magma, which is molten rock that forms within the Earth. A magma source rising from deep within the interior of the Earth has a different chemical composition than magma that forms just below the Earth’s crust. Some large oceanic plateaus exhibit signs of a deep-mantle origin. Others exhibit chemical signatures indicative of magma originating from a much shallower depth.

The IODP Shatsky Rise expedition focused on deciphering the relationship between supervolcano formation and the boundaries of tectonic plates, which may prove crucial to understanding what triggers supervolcano formation. A widely-accepted explanation for oceanic plateaus is that they form when a huge blob of magma source (a “plume head”) rises from deep in the Earth to the surface. An alternative theory suggests that large oceanic plateaus can originate at the intersection of three tectonic plates, known as a “triple junction,” but this mechanism is poorly understood. Shatsky Rise could play a key role in this debate, because it formed at a triple junction, but also displays certain characteristics that could be explained by the plume head model.

“Shatsky Rise is one of the best places in the world to study the origin of supervolcanoes,” Sager pointed out. “What makes Shatsky Rise unique is the fact that it is the only supervolcano to have formed during a time when Earth’s magnetic field reversed frequently.” This process creates “magnetic stripe” patterns in the seafloor. As Sager explained, “We can use these magnetic stripes to decipher the timing of the eruption and the spatial relationship of Shatsky Rise to the surrounding tectonic plates and triple junctions.”

According to preliminary results, sediments and microfossils collected during the expedition indicate that parts of the Shatsky Rise plateau were at one time at or above sea level, and formed an archipelago during the early Cretaceous period (about 145 million years ago). Shipboard lab studies further show that much of the lava erupted rapidly and that Shatsky Rise formed at or near the equator. As analyses continue in the months and years ahead, data collected during this expedition may help scientists to resolve the 50 year-old debate about the origin and nature of large oceanic plateaus.

IODP Expedition 324 “Shatsky Rise Formation” took place onboard the scientific ocean drilling vessel JOIDES Resolution from September 4 to November 4, 2009. The JOIDES Resolution is one of the primary research vessels of IODP, an international marine research program dedicated to advancing scientific understanding of the Earth through drilling, coring, and monitoring the subseafloor. The vessel is operated by the U.S. Implementing Organization of IODP, consisting of the Consortium for Ocean Leadership, Texas A&M University, and Lamont-Doherty Earth Observatory of Columbia University.

IODP is supported by two lead agencies, the U.S. National Science Foundation and Japan’s Ministry of Education, Culture, Sports, Science, and Technology. Additional program support comes from the European Consortium for Ocean Research Drilling (ECORD), the Australian-New Zealand IODP Consortium (ANZIC), India’s Ministry of Earth Sciences, the People’s Republic of China (Ministry of Science and Technology), and the Korea Institute of Geoscience and Mineral Resources.

For more information about IODP Expedition 324 – Shatsky Rise Formation, visit http://iodp.tamu.edu/scienceops/expeditions/shatsky_rise.html

For more information about the JOIDES Resolution, visit www.joidesresolution.org.

For more information about the Integrated Ocean Drilling Program, visit www.iodp.org.

Media Contacts: Kristin Ludwig Consortium for Ocean Leadership, Washington, D.C. USA +1-202-448-1254

Jamus Collier, Integrated Ocean Drilling Program Management International, Inc. (IODP-MI), Tokyo, Japan, +81-3-6701-3185

Kristin Ludwig | EurekAlert!
Further information:
http://www.oceanleadership.org
http://www.tamu.edu

More articles from Earth Sciences:

nachricht Impacts of mass coral die-off on Indian Ocean reefs revealed
21.02.2017 | University of Exeter

nachricht How much biomass grows in the savannah?
16.02.2017 | Friedrich-Schiller-Universität Jena

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Microhotplates for a smart gas sensor

22.02.2017 | Power and Electrical Engineering

Scientists unlock ability to generate new sensory hair cells

22.02.2017 | Life Sciences

Prediction: More gas-giants will be found orbiting Sun-like stars

22.02.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>