Featured Research

from universities, journals, and other organizations

'Treasure Trove' Of Climate Records Off Tahiti Coast: Coral Fossil Sampling To Document History Of Paleoclimatic Change

Date:
March 3, 2006
Source:
Integrated Ocean Drilling Program Management International
Summary:
An international team of scientists reunited to analyze a trove of coral fossil samples retrieved from Tahitian waters during October and November 2005. The initial conclusion is that the IODP Tahiti Sea Level Expedition has assembled the most accurate physical evidence available today of changes in sea level during the last deglaciation, including a full record of temperature and salinity changes in the southern Pacific.

Drilling sites of the Expedition 310.
Credit: Image courtesy of Earth Sciences and Image Analysis Laboratory, NASA Johnson Space Center

An international team of scientists, supported by the Integrated Ocean Drilling Program, reunited at the University of Bremen to analyze a trove of coral fossil samples retrieved from Tahitian waters during October and November 2005. Two weeks ago, led by chief scientists from France and Japan, the science party started their year-long analysis of 632 meters of fossil material retrieved from 37 boreholes drilled beneath the seafloor. The initial conclusion is that the IODP Tahiti Sea Level Expedition has assembled the most accurate physical evidence available today of changes in sea level during the last deglaciation, including a full record of temperature and salinity changes in the southern Pacific.

Co-chief scientist Gilbert Camoin, of CEREGE, a geoscience research center in France, summarized the expedition's success: "Tahiti has given us a treasure of records that archive sea level change over approximately the last 20,000 years. Because corals are ultra-sensitive to environmental change, we have been able--by splitting lengths of coral reef cores we acquired-- to get better, more accurate descriptions of reef growth during the sea level rise that occurred after the last glacial maximum, 23000 years ago." Camoin explains that Tahiti was chosen for this expedition because of its unique geology and its location: a relatively stable, volcanic island, Tahiti is subsiding at a rate of just .025 mm per year, in the southern Pacific far away from the previously glaciated regions. "Tahiti presents a microcosm of what's happening globally in paleoclimatology today," he says.

Japanese co-chief scientist Yasufumi Iryu, of Tohoku University, praises the quality of the cores obtained. "The longest continuous coral core we collected is 3.5 meters long," he confirms. "It represents 350 years of coral growth." Providing a reliable climate record with no gaps, massive coral samples--just five percent of the samples obtained--are highly valued by scientific investigators as they reconstruct climate variability and piece together frequency and amplitude of climatic anomalies such as El Niño.

"Our goal to acquire high-resolution archival paleoclimate records has been met," says Camoin. "Examining the massive coral cores retrieved from 40 to 120 meters below sea level, we identified grooved pairs of light and dark bands, each pair measuring a centimeter in width, and each representing one year of growth." According to Camoin, the coral fossils record age in their grooves. "Using radiometric methods, we are able to determine a coral fossil's age within 30 years."

Iryu, who specializes in El Niño anomalies, agrees that the age and water depth information found archived in the coral reef cores is simple, but crucial. In addition, "we measured live microbes (bacteria) living in the spaces within the deep fossil reefs. These samples," he confirmed, "have been collected and frozen for DNA sequencing."

"Coral reefs comprise the richest ecosystem on Earth," says Camoin, "and the most fragile." But coral reefs are diminishing, he notes: half of all reefs are expected to disappear in the next few decades. "Coral reefs are playing a prominent role in global matter cycles," Camoin asserts.


Story Source:

The above story is based on materials provided by Integrated Ocean Drilling Program Management International. Note: Materials may be edited for content and length.


Cite This Page:

Integrated Ocean Drilling Program Management International. "'Treasure Trove' Of Climate Records Off Tahiti Coast: Coral Fossil Sampling To Document History Of Paleoclimatic Change." ScienceDaily. ScienceDaily, 3 March 2006. <www.sciencedaily.com/releases/2006/03/060302091955.htm>.
Integrated Ocean Drilling Program Management International. (2006, March 3). 'Treasure Trove' Of Climate Records Off Tahiti Coast: Coral Fossil Sampling To Document History Of Paleoclimatic Change. ScienceDaily. Retrieved April 24, 2014 from www.sciencedaily.com/releases/2006/03/060302091955.htm
Integrated Ocean Drilling Program Management International. "'Treasure Trove' Of Climate Records Off Tahiti Coast: Coral Fossil Sampling To Document History Of Paleoclimatic Change." ScienceDaily. www.sciencedaily.com/releases/2006/03/060302091955.htm (accessed April 24, 2014).

Share This



More Earth & Climate News

Thursday, April 24, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

UN Joint Mission Starts Removing Landmines in Cyprus

UN Joint Mission Starts Removing Landmines in Cyprus

AFP (Apr. 23, 2014) — The UN mission in Cyprus (UNFICYP) led a mine clearance demonstration on Wednesday in the UN-controlled buffer zone where demining operations are being conducted near the Cypriot village of Mammari. Duration: 01:00 Video provided by AFP
Powered by NewsLook.com
California Drought Is Good News for Gold Prospectors

California Drought Is Good News for Gold Prospectors

AFP (Apr. 22, 2014) — For months California has suffered from a historic drought. The lack of water is worrying for farmers and ranchers, but for gold diggers it’s a stroke of good fortune. With water levels low, normally inaccessible areas are exposed. Duration: 01:57 Video provided by AFP
Powered by NewsLook.com
Raw: MN Lakes Still Frozen Before Fishing Opener

Raw: MN Lakes Still Frozen Before Fishing Opener

AP (Apr. 22, 2014) — With only three weeks until Minnesota's fishing opener, many are wondering if the ice will be gone. Some of the Northland lakes are still covered by up to three feet of ice, causing concern that just like last year, the lakes won't be ready. (April 22) Video provided by AP
Powered by NewsLook.com
Scientists Warn Of Likely El Niño Event This Year

Scientists Warn Of Likely El Niño Event This Year

Newsy (Apr. 22, 2014) — With Pacific ocean water already showing signs of warming, the NOAA says there's about a 66 percent chance the event will begin before November. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins