. Earth Science News .
CLIMATE SCIENCE
Barrier Reef corals help scientists calibrate ancient climate records
by Brooks Hays
Washington (UPI) Jun 18, 2019

Corals can help scientists track ancient climate patterns, but new research suggests that traditional analysis methods for analyzing coral's ancient growth aren't as accurate as previously thought.

Luckily, scientists have developed an improved method, a combination of high-resolution microscopic analysis and geochemical modeling. Researchers described the new technique this week in the journal Frontiers in Marine Science.

Deciphering the climate records coded in coral skeletons is similar to deciphering tree rings. As coral grows, new layers of calcium are deposited. Each layer traps geochemical signatures that can provide clues to the climatic conditions.

By measuring the amount of strontium and the lighter isotope of oxygen trapped in different calcium layers, scientists can estimate ancient sea surface temperatures. However, the technique isn't perfect.

Researchers compared coral-based sea-surface temperature records against temperature probe measurements.

"Remarkably, the coral records are accurate most of the time, but there are instances where measurements have been off by as much as nine degrees Celsius, and this needs to be rectified," Bruce Fouke, a professor of geology and microbiology at the University of Illinois, said in a news release.

As they grow, coral polyps deposit aragonite, a crystallized form of calcium carbonate. Unfortunately for climate scientists, seawater can also deposit aragonite crystals as it passes through the coral skeleton. Through a process called diagenesis, these seawater-derived crystals can alter the skeleton's chemistry.

"It is difficult to tell the diagenetic aragonite from the original coral skeleton without using high-powered microscopes," said Kyle Fouke, an undergraduate student at Bucknell University. "It is also challenging to know exactly when the diagenetic alteration took place -- days or decades after the skeletons were formed. Unless you are using the newest microscopy techniques to help select your samples, you could be collecting and measuring a mix of the two very different temperature records."

To better understand the effects of diagenetic aragonite, scientists surveyed Porites coral skeletons growing on the Great Barrier Reef.

"Based on our analyses, we see that the older portions of the coral heads growing in deeper seawater contain a higher concentration of diagenetic aragonite," Fouke said.

The team of scientists was able to differentiate between the coral and diagenetic aragonite using a combination of light, electron and X-ray microscopy techniques. The high-definition imaging techniques also revealed an array of different aragonite crystallization patterns. Scientists suggest some patterns represent seasonal variations in skeletal growth, while other smaller-scale patterns likely code geochemical changes on a daily cycle.

Researchers used their findings to develop a correction factor that can be applied to previous coral surveys and other climate studies that relied on aragonite analysis.

"Because this has been achieved using the carbonate mineral aragonite, which is ubiquitous among marine life, this same correction factor can be used with other sea creatures that secrete carbonate skeletons and shells," Fouke said.


Related Links
Climate Science News - Modeling, Mitigation Adaptation


Thanks for being here;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.
SpaceDaily Contributor
$5 Billed Once


credit card or paypal
SpaceDaily Monthly Supporter
$5 Billed Monthly


paypal only


CLIMATE SCIENCE
US regulator urges review of financial risk posed by climate change
New York (AFP) June 12, 2019
In the wake of renewed devastation from extreme weather in recent months, a top US financial regulator on Wednesday called for a comprehensive review of the risk posed by climate change. Global losses from natural disasters reached $160 billion in 2018, above the 30-year average of $140 billion, and that poses a risk to financial markets as well, said Rostin Behnam, a commissioner on the US Commodity Futures Trading Commission. "Our commodity markets and the financial markets that support them w ... read more

Comment using your Disqus, Facebook, Google or Twitter login.



Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle

CLIMATE SCIENCE
War, depression, suicide: American veterans are finding help

Rio's far-right governor would use 'a missile' against criminals

'I'm no hero' says Chernobyl diver portrayed in hit TV series

Elephants take more direct paths through dangerous territory

CLIMATE SCIENCE
Earth's heavy metals result of supernova explosion, University of Guelph research reveals

Mantis shrimp shield inspires lightweight, impact-resistant materials

Chemists develop faster way to purify elements

One more time: 2020 Olympic podiums to be made from recycled plastic

CLIMATE SCIENCE
Plankton species uses bioluminescence to scare off predators

Palau changes ocean sanctuary plan to allow Japan fishing

US prosecutor drops charges, starts over in criminal probe of tainted water

Earth's freshwater future: extremes of flood and drought

CLIMATE SCIENCE
Warming waters threaten large invertebrates in the Arctic

Jakobshavn glacier grows for third straight year

2,000 air force personnel from 4 nations join Red Flag-Alaska exercises

Senate calls on Canada to take a firm stand on Arctic sovereignty

CLIMATE SCIENCE
Tough sell: Baijiu, China's potent tipple, looks abroad

Demand for agricultural products pushing primates to brink of extinction

Heavy toll for French farms and vineyards after brutal hailstorm

In Germany, activists battle food waste with dumpster diving

CLIMATE SCIENCE
China earthquake kills 12, injures 134

Winds, rain batter western India as cyclone veers away

India to evacuate 300,000 from cyclone

Scientists figured out how tides cause earthquakes

CLIMATE SCIENCE
Two gendarmes, soldier killed in Mali violence: armed forces

China, Russia reject calls for freeze on UN pullout from Sudan

W.African farm 'bootcamp' gets green entrepreneurs into shape

African space industry now generating over 7B USD annually

CLIMATE SCIENCE
9,000 years ago, a community with modern urban problems

Human brain uniquely tuned for musical pitch

Oldest flaked stone tools point to the repeated invention of stone tools

Milk teeth reveal previously uknown Ice Age people from Siberia









The content herein, unless otherwise known to be public domain, are Copyright 1995-2024 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. General Data Protection Regulation (GDPR) Statement Our advertisers use various cookies and the like to deliver the best ad banner available at one time. All network advertising suppliers have GDPR policies (Legitimate Interest) that conform with EU regulations for data collection. By using our websites you consent to cookie based advertising. If you do not agree with this then you must stop using the websites from May 25, 2018. Privacy Statement. Additional information can be found here at About Us.