Lystrosaurus: The Most Humble Badass of the Triassic
by Annalee Newitz
One of the greatest survivors in all of Earth’s history was a humble creature named Lystrosaurus. It was a dog-sized animal whose peculiar lineage evolved about 270 million years ago, and looked like a cross between a pig and a lizard. Snub-faced and splay-legged, it was a burrower with powerful front legs who probably dug its own den every night. And somehow, it managed to survive the worst mass extinction the world has ever known.
About 250 million years ago, at the close of the Permian period, an enormous volcano called an igneous province started erupting in the region of the world that would one day be Siberia. At the time, this volcano was at the northern tip of a supercontinent called Pangaea that stretched from the north pole all the way down to the south. The eruption formed massive vents, rifts in the earth that released wave after wave of lava, along with billowing clouds of ash, carbon, and other toxins.
The Siberian igneous province laid waste to the environment for over a thousand years, ultimately releasing as much as to 43,000 gigatons of carbon into the atmosphere. It’s likely that the planet cooled down for a time, then heated up into a devastatingly profound greenhouse. At the same time, all that carbon caused ocean acidification. The resulting climate changes ultimately killed off 95 percent of all species on Earth.
Local and Global Impacts of the 1783-84 Laki Eruption in Iceland
by Erik Klemetti
Saturday marks the 230th anniversary of the famed Laki (or Skaftár Fires) eruption in Iceland — one of the largest volcanic eruptions in recorded history. It wasn’t a enormous explosion like many people associate with giant eruptions, nothing like Tambora or Krakatau.
However, it did have a profound impact on people living around the entire Northern Hemisphere for years afterwards, although the direct impact the eruption had on the Earth’s climate is still a widely debated and researched topic. In honor of this anniversary, I thought I’d try to give a brief primer on the eruption and why it is such an important eruption, both in terms of Icelandic volcanism and its global impact…
Antarctica’s Mountains Revealed by Sharpest Map Yet
by Christine Dell’Amore
Buried under miles of ice, Antarctica’s mysterious mountain ranges are coming into sharper focus thanks to a new map.
Created by the British Antarctic Survey, Bedmap2 drew upon millions of new measurements of the frozen continent’s surface elevation, ice thickness, and bedrock topography from a wide variety of sources collected over several decades.
Due to technological advances, Bedmap2 is also higher in resolution, more precise, and covers more of the continent than the original Bedmap, produced more than ten years ago, according to Charles Webb, deputy program scientist for cryospheric sciences at NASA headquarters. Earth’s frozen regions are collectively called the cryosphere…
We just finished two cruises investigating the U.S. Atlantic Canyons. Up next, the Okeanos will be mapping over a portion of the New England Seamount Chain. From hydrothermal vents to canyons to seamounts and more, there are so many interesting features to explore in the ocean.
If you were leading a research expedition, what feature(s) would YOU want to explore?
… at 8:32 a.m. Pacific Daylight Time, a magnitude 5.1 earthquake shook Mount St. Helens. The bulge and surrounding area slid away in a gigantic rockslide and debris avalanche, releasing pressure, and triggering a major pumice and ash eruption of the volcano. Thirteen-hundred feet (400 m) of the peak collapsed or blew outwards.
As a result, 24 square miles (62 sq km) of valley was filled by a debris avalanche, 250 square miles (650 sq km) of recreation, timber, and private lands were damaged by a lateral blast, and an estimated 200 million cubic yards (150 million cu m) of material was deposited directly by lahars (volcanic mudflows) into the river channels.
Sixty-one people were killed or are still missing. USGS Photograph taken on May 18, 1980, by Austin Post.
A pocket of water some 2.6 billion years old — the most ancient pocket of water known by far, older even than the dawn of multicellular life — has now been discovered in a mine, near the city of Timmins in Ontario, Canada, 2 miles below the Earth’s surface.
The Madrean Sky Island Archipelago is a 70,000-square-mile (180,000-square-kilometer) region of northwestern Mexico, southwestern New Mexico and southeastern Arizona. The region is a blend of tropical and temperate climates and home to a biological diversity that exceeds any other region of the United States.
Sky Islands are a class of continental terrain made up from a sequence of alternating valleys and mountains ranges. All sky islands have a stack of biotic communities that allow for vertical migration but the vast valleys between them act as a barrier preventing species from crossing from one mountain range to another…
After several days of lost dives due to bad weather and making dives under difficult conditions, we are today in calm seas exploring an area that was discovered last year during a NOAA mapping cruise. While conducting a seafloor survey, NOAA Ship Okeanos Explorer found bubbles coming from the seafloor at a site south and offshore of Norfolk Canyon; they thought these bubbles may indicate a new methane seep site, but they had no way of verifying this idea.
Today, we deployed the Jason remotely operated vehicle (ROV) from the NOAA Ship Ron Brown to 1,600 meters (nearly a mile deep—our deepest dive yet!) to explore the area around those bubbles. After transecting over soft sediment for a short time, we saw some indications that we were getting close to a probable methane seep. These indications included white patches of bacteria on the sediment surface that feed on the methane and sulfides, plus shells of dead mussels, which are the dominant animals of methane seep communities…
Lake Natron, located in Tanzania, is said by NASA to be the world’s most caustic body of water. Fed by mineral rich hotsprings, constant evaporation concentrates salts, leaving water that has a pH of 9 - 10.5 (almost the pH of household ammonia!).
Despite the hostility of the habitat, the high salt levels and pH are ideal environments for halophiles, microscopic organisms that are adapted to salt. Cyanobacteria and spirulina, which are responsible for the red colour of the lake, photosynthesise and provide energy for more complex organisms to feed on.
The Lake is the only regular breeding place for 2.5 million Lesser Flamingos(Phoenicopterus minor) which feed on the spirulina in the lake. The birds take advantage of the deterrent waters and plentiful amounts of food provided in an otherwise harsh environment.
The Alkaline Tilapia fish (Alcolapia sp.) also live in the waters, inhabiting the niches at the edges of hot spring inlets. They are well adapted to the high temperatures (up to 110°F or 43°C) and pH of the lake. The fish excrete urea, as the usual ammonia is hard to diffuse in the environment. They can also gulp atmospheric air to compensate for the hypoxic waters.
This image covers many shallow irregular pits with raised rims, concentrated along ridges and other topographic features. How did these odd features form?
One idea is that they could be from sublimation of shallow lenses of nearly pure ice, but why do the pits have raised rims? They can’t be impact craters with such fortuitous alignment and irregular margins. They aren’t wind-blown deposits because there are many boulders, too big to be moved by the wind. There are younger wind-blown drifts on top of the pits, and there’s no clear connection to volcanism.
Some speculate that there were ancient oceans over this region—could that somehow explain these features? Ancient glaciation is another possibility, perhaps depositing ice-rich debris next to topographic obstacles.Future images of this region may provide clues, but for now this is a mystery.
(via: HRISE - University of Arizona) (image: NASA/JPL/U of Az)
Dinosaur predecessors gain ground in wake of world’s biggest biodiversity crisis
Many scientists have thought that dinosaur predecessors missed the race to fill habitats emptied when nine out of 10 species disappeared during the Earth’s largest mass extinction, approximately 252 million years ago. The thinking was based on fossil records from sites in South Africa and southwest Russia. It turns out that scientists may have been looking for the starting line in the wrong places.
Newly discovered fossils from 10 million years after the mass extinction reveal a lineage of animals thought to have led to dinosaurs taking hold in Tanzania and Zambia in the mid-Triassic period, many millions of years before dinosaur relatives were seen in the fossil record elsewhere on Earth.
“The fossil record from the Karoo of South Africa remains a good representation of four-legged land animals across southern Pangea before the extinction event. But after the event animals weren’t as uniformly and widely distributed as before. We had to go looking in some fairly unorthodox places,” said Christian Sidor, University of Washington professor of biology. He’s lead author of a paper appearing the week of April 29 in the early edition of the Proceedings of the National Academy of Sciences…
Remnants of supernova explosion found in ancient magnetotactic bacteria
by John Hewitt
Back in 2004, German scientists discovered traces of supernova ejecta that had been deposited in the deep-sea ferromanganese crust of the pacific ocean. They dated the supernova event to 2.8 million years ago (Mya), using estimates from the decay of iron-60 radioisotope. They were also able to estimate the distance of the supernova event to 10 parsecs (pc) from our sun, based on the amount of iron-60 deposited.
At the April 14th meeting of the American Physical Society, a Canadian scientist, Shawn Bishop, reported finding traces of iron-60 of supernova origin in the fossilized remains of a common bacteria. By accurately dating the sediment cores in which the samples were found, Bishop appears to have discovered the first biological signature of an ancient supernova event, and may even be able to link it to a specific exploding star…