Understanding the structure of subducting plates

January 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: Solomon Islands earthquake sheds light on enhanced tsunami risk

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

Related Stories

Fingerprinting slow earthquakes (w/Podcast)

April 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 Alex Song of ...

Plate tectonics modelled realistically

February 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 rather than both ...

Model describes New Zealand's complex tectonic environment

March 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

A cataclysmic event of a certain age

July 27, 2015

At the end of the Pleistocene period, approximately 12,800 years ago—give or take a few centuries—a cosmic impact triggered an abrupt cooling episode that earth scientists refer to as the Younger Dryas.

'Carbon sink' detected underneath world's deserts

July 28, 2015

The world's deserts may be storing some of the climate-changing carbon dioxide emitted by human activities, a new study suggests. Massive aquifers underneath deserts could hold more carbon than all the plants on land, according ...

0 comments

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.