Community briefs

Tuesday, November 24, 1998

Community briefs

Plume of rock found on ocean floor near Hawaii

A massive plume of hot rock rising through the Earth and
erupting through the ocean floor has been building islands in the
central Pacific, including those of Hawaii, for at least 80 million
years.

Now scientists at the University of California, Santa Cruz, may
have located the origin of the Hawaiian plume at the boundary
between Earth’s mantle layer and its metallic core.

How deep the Hawaiian plume extends has long been a subject of
debate among earth scientists, said Sara Russell, a UCSC earth
sciences graduate student.

Russell worked with Thorne Lay, professor and chair of earth
sciences at UCSC, and Edward Garnero, research seismologist at the
UC Berkeley Seismological Laboratory, on the new study, published
in the Nov. 19 issue of the scientific journal Nature.

The researchers found evidence of the Hawaiian plume at the very
base of the mantle, about 1,800 miles (2,890 km) beneath the
surface of the Earth. Here, the molten outer layer of the Earth’s
core heats the overlying rock at the base of the mantle.

Using seismic waves generated by earthquakes to probe these deep
layers of the Earth, Russell identified a structural pattern in the
boundary layer between the mantle and the core that suggests
material is flowing horizontally toward the base of the Hawaiian
hotspot and then rising vertically.

"We’re seeing a change from horizontal to vertical structure
that seems to be related to the Hawaiian plume," Russell said.

The Hawaiian hotspot is the most productive plume-related
hotspot in the world, said Lay. Its volcanic eruptions have built
underwater mountains that eventually emerged from the sea as
islands.

Hawaii’s Mauna Loa, for example, is the most massive mountain on
Earth, occupying 10,000 cubic miles and rising 30,000 feet from the
seafloor.

Researchers

create search engine for DNA

Researchers at the University of California, San Diego (UCSD),
and the San Diego Supercomputer Center (SDSC) announced the
availability of a powerful, Web-accessible computational tool,
called Meta-MEME.

It will help biologists detect shared features and evolutionary
relationships among the growing stream of protein and DNA sequence
data being produced by the Human Genome Project and related
sequencing efforts.

"Meta-MEME detects these family relationships by analyzing
evolutionary fingerprints in the sequences with methods more common
in speech recognition software," said William Grundy of UCSD.

In a sense, Meta-MEME listens to the echoes of evolution, spoken
in the language of protein sequences.

Molecular biologists worldwide can tap transparently into the
computational power at SDSC by using the Meta-MEME software on the
Web (http://metameme.sdsc.edu/). It was created by Grundy and
Charles Elkan in the Computer Science and Engineering department of
UCSD’s Irwin and Joan Jacobs School of Engineering and Timothy
Bailey at SDSC.

Meta-MEME compares families of evolutionarily related DNA or
protein sequences using a Sun Microsystems Enterprise Server 10000
at SDSC.

The Meta-MEME project is funded by the National Biomedical
Computation Resource of SDSC, UCSD, and The Scripps Research
Institute.

A biologist begins by submitting a family of similar DNA or
protein sequences for analysis. After that, the entire Meta-MEME
process is automatic. The biologist submits sequences and the MEME
analysis via the Meta-MEME Web site, and up to four sets of results
are e-mailed to the user.

Compiled from Daily Bruin staff reports

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