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Acid raid, ozone depletion contributed to ancient extinction

By Guest PostDecember 2, 2013Science3d modeling technique, acid raid, ancient extinction, arctic siberia, atmospheric effects, base, benjamin black, carbon dioxide, christine shields, CO2, earth history, ecological diversity, fluctuations in ph, global ozone collapse, jean francois lamarque, jeffrey kiehl, kotuy river, linda elkins tanton, mass extinction, massachusetts institute, ozone depletion, permian mass extinction, permian period, rise of dinosaurs, russia, Siberia, siberian traps, so2, sulfur dioxide, Technology, terrestrial species, ultraviolet radiation, volcanic eruptions, volcanic rock, volcanic sequence

Washington, D.C.— Around 250 million years ago, at the end of the Permian period, there was a mass extinction so severe that it remains the most traumatic known species die-off in Earth’s history. Some researchers have suggested that this extinction was triggered by contemporaneous volcanic eruptions in Siberia. New results from a team including Director of Carnegie’s Department of Terrestrial Magnetism Linda Elkins-Tanton show that the atmospheric effects of these eruptions could have been devastating. Their work is published in Geology.

The mass extinction included the sudden loss of more than 90 percent of marine species and more than 70 percent of terrestrial species and set the stage for the rise of the dinosaurs. The fossil record suggests that ecological diversity did not fully recover until several million years after the main pulse of the extinction. (more…)

Scientists Find Possible Solution to an Ancient Enigma

By Guest PostJune 20, 2013Environmentamoeba, ancient enigma, anna mcintyre wressnig, calcium carbonate, cat scans, ciliates, clotted stones, coastal sediment, colchicine, disappearance, earth history, evolution, extinction of dinosaurs, foraminifera, geobiologist, highborne cay, hypotheses, joan bernhard, layered rocks, life on earth, meteorite, microbes, microbial ecologist, microfabric, minerals, multicellular life, oceanic sediments, paleontologists, photosynthetic cyanobacteria, proterozoic eon, protozoa, remote valleys, rrna, scientists, sediment, solution, stromatolites, thecate, thrombolites, velociraptors, virginia edgcomb, whoi

The widespread disappearance of stromatolites, the earliest visible manifestation of life on Earth, may have been driven by single-celled organisms called foraminifera.

The findings, by scientists at Woods Hole Oceanographic Institution (WHOI); Massachusetts Institute of Technology; the University of Connecticut; Harvard Medical School; and Beth Israel Deaconess Medical Center, Boston, were published online the week of May 27 in the Proceedings of the National Academy of Sciences. (more…)

Moon and Earth have common water source

By Guest PostJune 16, 2013Sciencealberto saal, amounts of deuterium, apollo missions, carnegie institution, common water source, crystal, earth, earth history, erik hauri, extra neutron, hydrogen deuterium ratios, inner solar system, james van orman, lunar rock, malcolm rutherford, moon, multicollector ion microprobe, nasa spacecraft, olivine, volatile elements, Washington

Researchers used a multicollector ion microprobe to study hydrogen-deuterium ratios in lunar rock and on Earth. Their conclusion: The Moon’s water did not come from comets but was already present on Earth 4.5 billion years ago, when a giant collision sent material from Earth to form the Moon.

PROVIDENCE, R.I. [Brown University] —Water inside the Moon’s mantle came from primitive meteorites, new research finds, the same source thought to have supplied most of the water on Earth. The findings raise new questions about the process that formed the Moon. (more…)

Fossil Raindrop Impressions Imply Greenhouse Gases Loaded Early Atmosphere

By Guest PostApril 2, 2012Environmentames research center, atmosphere, atmospheric pressure, concentration, david catling, earth history, fossilized, greenhouse gases, jelte harnmeijer, latex peels, liquid water, low carbon innovation, peter polivka, pressure broadening, raindrop impression, raindrop velocity, roger buick, sanjoy som, seattle, South Africa, sun, temperature, warm temperature

In ancient Earth history, the sun burned as much as 30 percent dimmer than it does now. Theoretically that should have encased the planet in ice, but there is geologic evidence for rivers and ocean sediments between 2 billion and 4 billion years ago.

Scientists have speculated that temperatures warm enough to maintain liquid water were the result of a much thicker atmosphere, high concentrations of greenhouse gases or a combination of the two. (more…)

Tag Archives: earth history

Acid raid, ozone depletion contributed to ancient extinction

Scientists Find Possible Solution to an Ancient Enigma

Moon and Earth have common water source

Fossil Raindrop Impressions Imply Greenhouse Gases Loaded Early Atmosphere