Liverpool scientist discovers new layer of the Earth

Apr 14, 2005

A University of Liverpool scientist has discovered a new layer near the Earth's core, which will enable the internal temperature of the Earth's mantle to be measured at a much deeper level than previously possible.

Dr Christine Thomas, from the Department of Earth Sciences, has found a previously undetected seismic layer near the Earth's core-mantle boundary. Her discovery will allow geophysicists to measure variations in the Earth's internal temperature near the boundary between the rocky mantle and fluid core, about 2,900 km below the Earth's surface.

Dr Thomas developed a model with colleagues at University of California Los Angeles (UCLA), which uses a recently discovered phase change (when atoms are compressed into crystals under high pressure) in the lowest part of the Earth's mantle. They propose that temperature changes in this area can result in the creation of two seismic layers near the core-mantle boundary, the second of which has been recently discovered by Dr Thomas.

The two seismic layers can provide a sensitive thermometer with which researchers can take the temperature of the Earth's lowermost mantle. The layers also enable scientists to examine whether cold subducted lithosphere (cold areas beneath a plate which can cause earthquakes) is reaching the core-mantle boundary, and whether hot material rises from the area between the core and mantle.

In the first case, the two seismic layers should be visible in seismic waves that travel through the Earth; the latter case would not show any layers. This would be a strong case for the convection of the whole mantle that is still a highly debated issue in the Earth Sciences.

Dr Thomas said: "Our discovery marks an exciting stage in earth science research as it provides the possibility to test the debated issue of whole mantle convection, the largely unconstrained heat flow from the Earth's core to the mantle and the fate of subducted lithosphere with seismic data."

Source: University of Liverpool

Explore further: Start of dwarf planet mission delayed after small mix-up

Related Stories

Seismic study aims to map Earth's interior in 3-D

Mar 16, 2015

When a 7.9-magnitude earthquake struck central China's Sichuan province in 2008, seismic waves rippled through the region, toppling apartment houses in the city of Chengdu and swaying office buildings 1,000 ...

Recommended for you

The riddle of galactic thin–thick disk solved

Apr 24, 2015

A long-standing puzzle regarding the nature of disk galaxies has finally been solved by a team of astronomers led by Ivan Minchev from the Leibniz Institute for Astrophysics Potsdam (AIP), using state-of-the-art ...

Giant cosmic tsunami wakes up comatose galaxies

Apr 24, 2015

Galaxies are often found in clusters, with many 'red and dead' neighbours that stopped forming stars in the distant past. Now an international team of astronomers, led by Andra Stroe of Leiden Observatory ...

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.