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: A 3-D view of the Greenland Ice Sheet opens window on ice history

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

Geologists solve mystery of Tibetan mountains

Jan 23, 2015

In the most comprehensive study of its kind, University of Kansas geologists have unraveled one of the geologic mysteries of Tibet. The research, recently published online in Nature Geoscience, shows that i ...

Image: Greenland's Leidy Glacier

Jan 23, 2015

Located in the northwest corner of Greenland, Leidy Glacier is fed by ice from the Academy Glacier (upstream and inland). As Leidy approaches the sea, it is diverted around the tip of an island that separates ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.