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
Further reports about: > Ancient African Exodus > Deciphering Dolphin Language > Earth's magnetic field > Earth’s surface > IODP > Integrated Ocean Drilling Program > JOIDES > Pacific Ocean > Science TV > greenhouse gas > information technology > magma source > mass extinction > ocean floor > oceanic plate > seafloor > tectonic plate
Receding glaciers in Bolivia leave communities at risk
20.10.2016 | European Geosciences Union
UM researchers study vast carbon residue of ocean life
19.10.2016 | University of Miami Rosenstiel School of Marine & Atmospheric Science
Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.
"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...
In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.
A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...
By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.
"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...
COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.
In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...
'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.
Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...
14.10.2016 | Event News
14.10.2016 | Event News
12.10.2016 | Event News
21.10.2016 | Health and Medicine
21.10.2016 | Information Technology
21.10.2016 | Materials Sciences