Understanding the structure of subducting plates

Jan 29, 2013

Seismic studies are helping scientists learn more about the structure of subducting oceanic plates.

Using an airgun array and 80 seismometers spaced along a 500 kilometer (310 mile) profile, Fujie et al. conducted a seismic reflection and refraction survey at the Kuril trench in the northwestern Pacific margin, where part of the Pacific plate is subducting beneath the Okhotsk plate.

They estimate the water content of the subducting plate by measuring the velocity of seismic waves—both P waves and S waves—through the plate. The V sub p over V sub s ratio is an indicator of the lithology, porosity, and presence of fluid in the plate.

Their findings show that the water content in the plate increased toward the trench, along with greater bending and fracturing, suggesting that water enters the plate through the fractures.

The authors conclude that the bending and fracturing of the plate as it subducts plays an important role in the water cycle in .

Explore further: Quakes destroy or damage 83 houses in Philippines

More information: Systematic changes in the incoming plate structure at the Kuril trench, Geophysical Research Letters, doi: 10.1029/2012GL054340, 2013 http://onlinelibrary.wiley.com/doi/10.1029/2012GL054340/abstract

add to favorites email to friend print save as pdf

Related Stories

Plate tectonics modelled realistically

Feb 23, 2012

Swiss scientists have for the first time succeeded in realistically simulating how an oceanic plate sinks of its own accord under an adjacent plate. At the same time they showed why only one of the plates ...

Fingerprinting slow earthquakes (w/Podcast)

Apr 23, 2009

(PhysOrg.com) -- The most powerful earthquakes happen at the junction of two converging tectonic plates, where one plate is sliding (or subducting) beneath the other. Now a team of researchers, led by Teh-Ru ...

Model describes New Zealand's complex tectonic environment

Mar 19, 2012

At the Hikurangi fault, off the eastern coast of New Zealand's North Island, the Pacific tectonic plate sinks beneath the Australian plate. Farther south, in the Marlborough Fault System, which cuts through the country's ...

Recommended for you

Kiribati leader visits Arctic on climate mission

Sep 20, 2014

Fearing that his Pacific island nation could be swallowed by a rising ocean, the president of Kiribati says a visit to the melting Arctic has helped him appreciate the scale of the threat.

NASA catches a weaker Edouard, headed toward Azores

Sep 19, 2014

NASA's Aqua satellite passed over the Atlantic Ocean and captured a picture of Tropical Storm Edouard as it continues to weaken. The National Hurricane Center expects Edouard to affect the western Azores ...

User comments : 0