In early March, an international team of scientists will set sail aboard the drill ship JOIDES Resolution on the first of two Integrated Ocean Drilling Program (IODP) expeditions to the equatorial Pacific Ocean. The second expedition will follow immediately afterward in May. Both are grouped into one science program, known as the Pacific Equatorial Age Transect (PEAT).
will lead to a clearer understanding of Earth's climate over the past 55
million years – a vital component to knowing what future course the planet's
climate will take, scientists believe.
expeditions focused on climate change come at a critical time," says Julie
Morris, director of the National Science Foundation (NSF)'s Division of Ocean
Sciences, which supports IODP. "During the next year, sea-floor drilling
related to climate change will happen from pole to pole."
expeditions aim to recover a continuous Cenozoic record (from 65.5 million
years ago to the present) of sediments beneath the equatorial Pacific Ocean.
Geologists will drill into the crust on the Pacific tectonic plate along the
research effort, Expedition 320, is planned for March 5 through May 5, 2009;
Expedition 321 will take place from May 5 through July 5, 2009.
scientists of Expedition 320 are Heiko Palike of the University of Southampton,
U.K., and Hiroshi Nishi of Hokkaido University in Japan; of Expedition 321,
Mitch Lyle of Texas A&M University in the U.S., and Isabella Raffi of the
Universita "G. D'Annunzio" Campus Universitario in Italy.
scientific ocean drilling expeditions to the equatorial Pacific yielded
discoveries about past climate conditions and the past position of the Pacific
tectonic plate relative to the equator. However, they did not obtain continuous
sediment records the two PEAT expeditions will recover seafloor sediment cores
with an unbroken record.
cores will help us understand how and why productivity in the Pacific changed
over time," explains Morris, "and provide information about rapid
biological evolution and turnover during times of climatic stress."
equatorial Pacific is a major center of solar warming, a region of high
productivity, and a primary region for carbon dioxide exchange from the deep
ocean to the atmosphere. It also is the source region for the El Niño-Southern
Oscillation phenomenon. The equatorial Pacific helps maintain global climates,
and drives climate change.
last 55 million years, global climate has varied dramatically from extreme
warmth to glacial cold. These climate variations have been imprinted on the
biogenic-rich sediments that accumulated in the equatorial zone.
from the PEAT expeditions will help scientists understand how Earth was able to
maintain very warm climates relative to the 20th century, even though solar
radiation received at the earth's surface has remained nearly constant for the
last 55 million years.
Two New Ocean Drilling Expeditions
March 4, 2009