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Mount Saint Helens - A Quiet Eruption
Posted on Tuesday, November 29, 2005 @ 3:11 pm by Dave Schumaker
The current eruption at Mount Saint Helens is now in its 15th month and no large plumes of ash have risen from the summit in the last 9 months. However, hot (and solid) rock are still being squeezed out of the summit at roughly one cubic yard every second. The Chicago Tribune has an article talking about the ongoing eruption.
Each second, about a cubic yard of new mountain–roughly a pickup truck’s worth–is pushed to the surface, adding to a dome growing in the crater.
In earlier months, the cylinder of new rock, which is about 200 yards in diameter, toppled to the side as it rose. Now, the new rock is buried beneath earlier material and just pushes up the entire hill.
Highest CO2 levels in 650 Ka
Posted on Friday, November 25, 2005 @ 9:47 am by Dave Schumaker
A new ice core drilled in Eastern Antarctica by European scientists offers an unprecedented look at CO2 levels during the last 650,000 years. According to new studies based on this ice core, CO2 levels are 27% higher than at any point during the last 650,000 years.
Today’s rising CO2 concentrations are 27 percent higher than at the highest level seen over the 650,000-year time scale, according to the study, which appears in the weekly US journal Science.
The Dome C core, extracted by the 10-country European Project for Ice Coring in Antarctica (EPICA), outstrips by 210,000 years the previous record-holder, drilled at an Antarctic site called Vostok.
Montagu Island Eruption Heats Up
Posted on Friday, November 25, 2005 @ 7:28 am by Ron Schott
File this one under “Satellites as Field Equipment”.
New satellite images show that Montagu Island, a volcano in the South Sandwich Islands, has grown by 50 acres (0.2 square kilometers) in the last month as lava pours into the sea.
“Red hot lava has formed a molten river 90 meters wide that is moving fast, possibly several meters per second and extending the shoreline on the north side of the island,” said John Smellie of British Antarctic Survey (BAS). “This event is special because Montagu Island is mostly ice covered and it’s very rare that we get to make direct observations of eruptions under ice sheets.”
Dinosaur’s Diet: Grass!
Posted on Monday, November 21, 2005 @ 8:51 am by Dave Schumaker
When most people think of the time the dinosaurs roam, and the plants associated with that period, thoughts of plush ferns and tall trees come to mind. According to new evidence found in fossilized dinosaur dung (also known as coprolite), grass was present at the time of the dinosaurs. It was originally thought that grass didn’t show up until 55 million years ago, after dinosaurs were extinct.
Fossilized dung tells the story: The most prominent plant-eating dinosaurs were digesting different varieties of grass between 65 million and 71 million years ago, researchers report Friday in the journal Science.
The earliest grass fossils ever found were about 55 million years old — from the post-dinosaur era.
Continents Present on Earth Earlier Than Thought?
Posted on Monday, November 21, 2005 @ 8:39 am by Dave Schumaker
Using a rare metal element called hafnium, a team of researchers have concluded that continents and other solid land masses were present on Earth much earlier than originally though. Their results indicate that continental crust was formed as early as 4.4 - 4.5 billion years ago.
“These results support the view that the continental crust had formed by 4.4-4.5 billion years ago and was rapidly recycled into the mantle,” the researchers wrote in Science Express. Led by Professor Mark Harrison of the Australian National University, the team also included University of Colorado Assistant Professor Stephen Mojzsis and researchers from the University of California, Los Angeles and Ecole Normale Superieure University in France.
The researchers used hafnium as a “tracer” element, using isotopes to infer the existence of early continental formation on Earth dating to Hadeon Eon, which took place during the first 500 million years of Earth’s history, said Mojzsis, an assistant professor of geological sciences at CU-Boulder. Mojzsis also is a member of CU-Boulder’s Center for Astrobiology.