Human Induced Climate Change Experiment

Home | Resources | Archives |Contact Us


Global Extinction: Gradual Doom as Bad as Abrupt

Global Extinction: Gradual Doom as Bad as Abrupt

In “The Great Dying” 250 million years ago, the end came slowly

Photo of Griesbach Creek in the Arctic.
The geology of Griesbach Creek in the Arctic tells an ancient tale of slow extinction.
Credit and Larger Version

February 2012

The deadliest mass extinction of all took a long time to kill 90 percent of Earth’s marine life–and it killed in stages–according to a newly published report.

It shows that mass extinctions need not be sudden events.

Thomas Algeo, a geologist at the University of Cincinnati, and 13 colleagues have produced a high-resolution look at the geology of a Permian-Triassic boundary section on Ellesmere Island in the Canadian Arctic.

Their analysis, published today in the Geological Society of America Bulletin, provides strong evidence that Earth’s biggest mass extinction phased in over hundreds of thousands of years.

About 252 million years ago, at the end of the Permian period, Earth almost became a lifeless planet.

Around 90 percent of all living species disappeared then, in what scientists have called “The Great Dying.”

Algeo and colleagues have spent much of the past decade investigating the chemical evidence buried in rocks formed during this major extinction.

The world revealed by their research is a devastated landscape, barren of vegetation and scarred by erosion from showers of acid rain, huge “dead zones” in the oceans, and runaway greenhouse warming leading to sizzling temperatures.

The evidence that Algeo and his colleagues are looking at points to massive volcanism in Siberia as a factor.

“The scientists relate this extinction to Siberian Traps volcanic eruptions, which likely first affected boreal life through toxic gas and ashes,” said H. Richard Lane, program director in the National Science Foundation’s (NSF) Division of Earth Sciences, which funded the research.

The Siberian Traps form a large region of volcanic rock in Siberia. The massive eruptive event which formed the traps, one of the largest known volcanic events of the last 500 million years of Earth’s geologic history, continued for a million years and spanned the Permian-Triassic boundary.

The term “traps” is derived from the Swedish word for stairs–trappa, or trapp–referring to the step-like hills that form the landscape of the region.

A large portion of western Siberia reveals volcanic deposits up to five kilometers (three miles) thick, covering an area equivalent to the continental United States. The lava flowed where life was most endangered, through a large coal deposit.

“The eruption released lots of methane when it burned through the coal,” Algeo said. “Methane is 30 times more effective as a greenhouse gas than carbon dioxide.

“We’re not sure how long the greenhouse effect lasted, but it seems to have been tens or hundreds of thousands of years.”

Much of the evidence was washed into the ocean, and Algeo and his colleagues look for it among fossilized marine deposits.

Previous investigations have focused on deposits created by a now vanished ocean known as Tethys, a precursor to the Indian Ocean. Those deposits, in South China particularly, record a sudden extinction at the end of the Permian.

“In shallow marine deposits, the latest Permian mass extinction was generally abrupt,” Algeo said. “Based on such observations, it has been widely inferred that the extinction was a globally synchronous event.”

Recent studies are starting to challenge that view.

Algeo and co-authors focused on rock layers at West Blind Fiord on Ellesmere Island in the Canadian Arctic.

That location, at the end of the Permian, would have been much closer to the Siberian volcanoes than sites in South China.

The Canadian sedimentary rock layers are 24 meters (almost 80 feet) thick and cross the Permian-Triassic boundary, including the latest Permian mass extinction horizon.

The investigators looked at how the type of rock changed from the bottom to the top. They looked at the chemistry of the rocks and at the fossils contained in the rocks.

They discovered a total die-off of siliceous sponges about 100,000 years earlier than the marine mass extinction event recorded at Tethyan sites.

What appears to have happened, according to Algeo and his colleagues, is that the effects of early Siberian volcanic activity, such as toxic gases and ash, were confined to the northern latitudes.

Only after the eruptions were in full swing did the effects reach the tropical latitudes of the Tethys Ocean.

The research was also supported by the Canadian Natural Sciences and Engineering Research Council and the National Aeronautics and Space Administration Exobiology Program.

In addition to Algeo, co-authors of the paper are: Charles Henderson, University of Calgary; Brooks Ellwood, Louisiana State University; Harry Rowe, University of Texas at Arlington; Erika Elswick, Indiana University, Bloomington; Steven Bates and Timothy Lyons, University of California, Riverside; James Hower, University of Kentucky; Christina Smith and Barry Maynard, University of Cincinnati; Lindsay Hays and Roger Summons, Massachusetts Institute of Technology; James Fulton, Woods Hole Oceanographic Institution; and Katherine Freeman, Pennsylvania State University.

-NSF-

This entry was posted in Uncategorized and tagged , , , , , , , , , , , . Bookmark the permalink. Post a comment or leave a trackback: Trackback URL.

Post a Comment

You must be logged in to post a comment.

  • RSS Membrane Domain

    • Global Warming Exponential Damage
      Real Estate USA & Center City Philadelphia Real Estate for Sale Learn How to Advertise Here Place Advertising Contact Us The U.N. Intergovernmental Panel on Climate Change reported that global warming is spiraling out of control. “The world, in many cases, is ill-prepared for risks from a changing climate,” the IPCC said. FAQ 1: Are […]
    • Washington Mudslide
      You would think with all the mud slinging in Washington DC that would be the Washington with the mudslide. No, the mudslide that killed over a dozen people and left over 100 missing was in Oso, Washington. Oso is a small village 55 miles northeast of Seattle (or, perhaps we should say *was*.) The village […]
    • News from the Ice Wars
      The Membrane Domain has been conducting Human Induced Climate Change Experiments since 1999. One of the first scientist to hypothesize that global warming was exponential (as opposed to the linear models) requested fellow scientists to conduct studies. One Membrane Domain scientists began a study on the decline of the ice mass. The analysis is on-going; […]
  • RSS Global Warming

    • Latest Mississippi River Delta News: April 18, 2014
      Coast Guard calls BP's spill cleanup claim premature By Collin Eaton, The Houston Chronicle. April 17, 2014. “The Coast Guard is crying foul at BP's statement this week announcing the end of active cleanup efforts to remove oil…” (read more) Coast Guard slams BP for suggesting oil spill cleanup is complete By Lindsay Abrams, Salon. April 17, 2014. […]
    • An In-Depth Look at the Future of American Energy and How We Get There
      By Cheryl Robertoistockphoto.com Imagine a world where homes not only run on clean electricity but also generate, store, and sell it. A world where power companies get paid for conserving energy, not just producing it. Where, when supplies are tight, the power grid gives customers the option of being paid to reduce and even shift their energy use to a differ […]
    • Community-based fishery management delivers individual and collective benefits in Belize
      Recently, I traveled to Belize to see how TURF-reserves (territorial use rights for fishing co-located with no-take zones) are performing and learn about plans to expand them nationwide. The Mesoamerican Reef, the largest in the Atlantic Ocean, spans the Belizean coastline and is rich in biodiversity and a crucial source of income for thousands of […] […]
  • RSS State Of The Climate

    • March 2014 National Overview
      Please see March 2014 National Overview report for more information.
    • March 2014 Drought
      During March 2014, a strong long-wave trough in the upper-level circulation remained entrenched over eastern Canada. The northerly flow over central North America, associated with the trough, directed cold and dry northerly air masses into the CONUS. This pattern brought below-normal temperatures to most of the country east of the Rockies and deflected much […]
    • March 2014 Synoptic Discussion
      The long-wave circulation pattern for March 2014 over North America was a continuation of the overall pattern seen throughout the winter, but with some changes. It consisted of a dominant upper-level trough over eastern Canada which extended into western Canada and the northeastern U.S., thus bisecting the upper-level ridge over western North America. Short- […]
  • RSS Global Climate Change – Vital Signs of the Planet – News RSS Feed

    • Building a better soybean for a hot, dry, hungry world
      [[IMAGE||/system/image_uploads/main/SuppAsoybeans.jpg||Right||250||Soybean seeds from the Soybean Germplasm Collection of the U.S. Department of Agriculture (USDA). Credit: USDA||Soybean seeds from the Soybean Germplasm Collection of the U.S. Department of Agriculture (USDA). Credit: USDA.||||||http://climate.nasa.gov/system/image_uploads/main/SuppAsoybeans. […]
  • RSS Natural Hazards

  • Archives

  • Archives