Tolstoy and Lamont-Doherty colleague Felix Waldhauser set an array of ocean bottom seismometers along a section of the East Pacific Rise off the coast of Mexico in 2003 to study the little-understood process of seafloor spreading--a process that is responsible for the formation of nearly three-quarters of the Earth's crust. When a team went back in April 2006 to retrieve the instruments, however, only four out of 12 responded to the coded release signal and bobbed to the surface; three more responded to the signal, but did not come up. The rest remained silent.
Tests of the water temperature and light-scattering near the sea floor revealed signs of a recent volcanic eruption. A second expedition led by James Cowen of the University of Hawaii on the research vessel R/V New Horizon in early May lowered a camera that confirmed what the scientists suspected: Their instruments had been directly on top of a section of the East Pacific Rise that erupted and were trapped in fresh lava flows.
Instead of bemoaning their fate, the group celebrated their fortune--no one has ever closely recorded the series of micro-earthquakes associated with the formation of new seafloor. Preliminary analysis of their data appears in an upcoming issue of the journal Science and will be released on the Science Express Web site November 23.
"It's amazing that we know so little about something so fundamental to the planet," said Tolstoy. "Even if we don't get the rest of the instruments back we'll have learned quite a bit."
The East Pacific Rise is one of three active seafloor spreading centers targeted by the National Science Foundation's Ridge 2000 program to document the process of crustal formation as it is happening. Ridge 2000 was formed in 2001 as an interdisciplinary effort to study the geology, chemistry and biology of the poorly understood process by which the Earth's crust is formed.
"Discovering new lava so soon after a seafloor eruption is a unique opportunity," said Donna Blackman, current chair of the Ridge 2000 program. "It allows Ridge researchers a rare chance to see how geologic processes affect the deep-sea ecosystems that thrive near hydrothermal vents."
The first underwater eruption was not documented until 1990, even though many probably occur each year, and seismometers on land still cannot detect the many small, distant earthquakes that scientists believe precede a submarine eruption for many months. By comparison, earthquakes often occur only a few days or hours before a land-based volcanic eruption.
Tolstoy found that seismic activity at the site gradually built up for at least two years leading up to the brief, January 2006 eruption that entombed her instruments, raising the possibility that future eruptions may be forecast a year or more in advance.
"Our success emphasizes the importance of real-time monitoring on the seafloor so that next time we'll be collecting many different types of data the moment an eruption starts," said Tolstoy. "That way we can really begin to understand this fundamental building block of our planet, from the mantle to the microbe.
New research calculates capacity of North American forests to sequester carbon
16.07.2018 | University of California - Santa Cruz
Scientists discover Earth's youngest banded iron formation in western China
12.07.2018 | University of Alberta
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.
Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...
13.07.2018 | Event News
12.07.2018 | Event News
03.07.2018 | Event News
18.07.2018 | Materials Sciences
18.07.2018 | Life Sciences
18.07.2018 | Health and Medicine