Free Newsletters - Space - Defense - Environment - Energy - Solar - Nuclear
..
. 24/7 Space News .




WATER WORLD
Modern Ocean Acidification Is Outpacing Ancient Upheaval
by Staff Writers
New York NY (SPX) Jun 03, 2014


Ocean acidification in the modern ocean may already be affecting some marine life, as shown by the partly dissolved shell of this planktic snail, or pteropod, caught off the Pacific Northwest. Image courtesy Nina Bednarsedk and NOAA.

Some 56 million years ago, a massive pulse of carbon dioxide into the atmosphere sent global temperatures soaring. In the oceans, carbonate sediments dissolved, some organisms went extinct and others evolved.

Scientists have long suspected that ocean acidification caused the crisis-similar to today, as manmade CO2 combines with seawater to change its chemistry. Now, for the first time, scientists have quantified the extent of surface acidification from those ancient days, and the news is not good: the oceans are on track to acidify at least as much as they did then, only at a much faster rate.

In a study published in the latest issue of Paleoceanography, the scientists estimate that ocean acidity increased by about 100 percent in a few thousand years or more, and stayed that way for the next 70,000 years.

In this radically changed environment, some creatures died out while others adapted and evolved. The study is the first to use the chemical composition of fossils to reconstruct surface ocean acidity at the Paleocene-Eocene Thermal Maximum (PETM), a period of intense warming on land and throughout the oceans due to high CO2.

"This could be the closest geological analog to modern ocean acidification," said study coauthor Barbel Honisch, a paleoceanographer at Columbia University's Lamont-Doherty Earth Observatory. "As massive as it was, it still happened about 10 times more slowly than what we are doing today."

The oceans have absorbed about a third of the carbon humans have pumped into the air since industrialization, helping to keep earth's thermostat lower than it would be otherwise. But that uptake of carbon has come at a price. Chemical reactions caused by that excess CO2 have made seawater grow more acidic, depleting it of the carbonate ions that corals, mollusks and calcifying plankton need to build their shells and skeletons.

In the last 150 years or so, the pH of the oceans has dropped substantially, from 8.2 to 8.1--equivalent to a 25 percent increase in acidity. By the end of the century, ocean pH is projected to fall another 0.3 pH units, to 7.8. While the researchers found a comparable pH drop during the PETM--0.3 units--the shift happened over a few thousand years.

"We are dumping carbon in the atmosphere and ocean at a much higher rate today-within centuries," said study coauthor Richard Zeebe, a paleoceanographer at the University of Hawaii. "If we continue on the emissions path we are on right now, acidification of the surface ocean will be way more dramatic than during the PETM."

The study confirms that the acidified conditions lasted for 70,000 years or more, consistent with previous model-based estimates. "It didn't bounce back right away," said Timothy Bralower, a researcher at Penn State who was not involved in the study. "It took tens of thousands of years to recover."

From seafloor sediments drilled off Japan, the researchers analyzed the shells of plankton that lived at the surface of the ocean during the PETM. Two different methods for measuring ocean chemistry at the time-the ratio of boron isotopes in their shells, and the amount of boron --arrived at similar estimates of acidification.

"It's really showing us clear evidence of a change in pH for the first time," said Bralower.

What caused the burst of carbon at the PETM is still unclear. One popular explanation is that an overall warming trend may have sent a pulse of methane from the seafloor into the air, setting off events that released more earth-warming gases into the air and oceans. Up to half of the tiny animals that live in mud on the seafloor-benthic foraminifera-died out during the PETM, possibly along with life further up the food chain.

Other species thrived in this changed environment and new ones evolved. In the oceans, dinoflagellates extended their range from the tropics to the Arctic, while on land, hoofed animals and primates appeared for the first time. Eventually, the oceans and atmosphere recovered as elements from eroded rocks washed into the sea and neutralized the acid.

Today, signs are already emerging that some marine life may be in trouble. In a recent study led by Nina Bednarsedk at the U.S. National Oceanic and Atmospheric Administration, more than half of the tiny planktic snails, or pteropods, that she and her team studied off the coast of Washington, Oregon and California showed badly dissolved shells.

Ocean acidification has been linked to the widespread death of baby oysters off Washington and Oregon since 2005, and may also pose a threat to coral reefs, which are under additional pressure from pollution and warming ocean temperatures.

"Seawater carbonate chemistry is complex but the mechanism underlying ocean acidification is very simple," said study lead author Donald Penman, a graduate student at University of California at Santa Cruz. "We can make accurate predictions about how carbonate chemistry will respond to increasing carbon dioxide levels. The real unknown is how individual organisms will respond and how that cascades through ecosystems."

Other authors of the study, which was funded by the U.S. National Science Foundation: Ellen Thomas, Yale University; and James Zachos, UC Santa Cruz.

.


Related Links
Lamont -Doherty Earth Observatory
Water News - Science, Technology and Politics






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

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




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News





WATER WORLD
Australian environmentalists welcome bank wariness on reef port
Sydney (AFP) May 24, 2014
Environmentalists on Saturday welcomed Deutsche Bank's reluctance to invest in a major port expansion near Australia's Great Barrier Reef, saying it reflected global concern about the project. Australia gave the green light to the major coal port expansion for India's Adani Group at Abbot Point on the Great Barrier Reef coast last year subject to strict environmental conditions. But con ... read more


WATER WORLD
NASA Missions Let Scientists See Moon's Dancing Tide From Orbit

Water in moon rocks provides clues and questions about lunar history

NASA Invites Public to Select Favorite Moon Image for Lunar Orbiter Anniversary Collection

LRO View of Earth

WATER WORLD
New Mars Lander to Probe Interior of Red Planet

A habitable environment on Martian volcano

Mars Curiosity rover may have transported Earth bacteria to Mars

NASA Mars Weather Camera Helps Find New Crater on Red Planet

WATER WORLD
Smart lifestyle takes centre stage at Asia tech show

German village takes digital fate into own hands

Ecosystem Services: Looking Forward to Mid-Century

Virgin space flights cleared for US take-off

WATER WORLD
Chinese lunar rover alive but weak

China's Jade Rabbit moon rover 'alive but struggling'

Chinese space team survives on worm diet for 105 days

Moon rover Yutu comes closer to public

WATER WORLD
Russian Soyuz with New Crew Docks at ISS in Automatic Mode

Russian, German and US astronauts dock with ISS

Six-Person Station Crew Enjoys Day Off Following Docking

ESA astronaut Alexander Gerst arrives at ISS

WATER WORLD
Elon Musk to present manned DragonV2 spacecraft on May 29

Russia puts satellite in orbit from sea platform after 2013 flop

SpaceX Completes Qualification Testing of SuperDraco Thruster

After Injunction lifted, US rocket with Russian RD-180 Engine takes off

WATER WORLD
Why Does Earth Have No Super-Earth Cousins?

Astronomers identify signature of Earth-eating stars

Starshade Could Help Photograph Distant Planets

Giant telescope tackles orbit and size of exoplanet

WATER WORLD
Stronger than steel

Researchers predict electrical response of metals to extreme pressure

Pitt team first to detect exciton in metal

Lasers create table-top supernova




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - 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. 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. Privacy Statement All images and articles appearing on Space Media Network have been edited or digitally altered in some way. Any requests to remove copyright material will be acted upon in a timely and appropriate manner. Any attempt to extort money from Space Media Network will be ignored and reported to Australian Law Enforcement Agencies as a potential case of financial fraud involving the use of a telephonic carriage device or postal service.