“After decades of little activity, a series of earthquakes and deformation began within the Santorini caldera in January of 2011,” said Newman, whose research is published by Geophysical Research Letters. “Since then, our instruments on the northern part of the island have moved laterally between five and nine centimeters. The volcano’s magma chamber is filling, and we are keeping a close eye on its activity.”
Newman, a geophysicist in the School of Earth and Atmospheric Sciences, cannot be certain whether an eruption is imminent since observations of such activity on these types of volcanoes are limited. In fact, similar calderas around the globe have shown comparable activity without erupting. However, Newman says the chamber has expanded by 14 million cubic meters since last January. That means enough magma has been pumped into the chamber to fill a sphere three football fields across.
Should Santorini erupt, Newman says it will likely be comparable to what the island has seen in the last 450 years.
“That could be dangerous,” notes Newman. “If the caldera erupts underwater, it could cause local tsunamis and affect boat traffic, including cruise ships, in the caldera. Earthquakes could damage homes and produce landslides along the cliffs.”
More than 50,000 tourists a day flock to Santorini in the summer months (from May to October). It’s common to see as many as five cruise ships floating above the volcano.
Santorini is the site of one of the largest volcanic events in human history. The Minoan eruption, which occurred around 1650 B.C., buried the major port city of Akrotiri with more than 20 meters of ash and created Santorini’s famous, present-day cliffs. Newman says such history will likely not repeat itself any time soon. Such an eruption comes along once every 100,000 years, and the current inflation in the magma chamber is less than 1 percent of the Minoan blast.
The submarine eruption south of El Hierro Island could be in a process of change: While visible activity on the sea surface above the vent, as well as harmonic tremor signal (thought to be more or less proportional to erupting magma flux) have nearly ceased, the number of earthquakes under the island has increased sharply since yesterday.
On 15 February, more than 20 quakes were measured. Most of the earthquakes were very small, well below magnitude 2, and were clustered beneath the NW and SW sectors of the island at depths of around 10 km. There is no conclusive interpretation of this measurement.
A possible (and usually assumed) scenario is that rising new magma from the mantle reservoir is creating new intrusions and rupturing rock to create pathways in the crust under El Hierro, not using the same paths as until now. That would explain why less magma is currently being erupted at the current vent(s). In that scenario, the eruption will continue, perhaps even from a different vent, and an increase in magma output is going to be expected any time soon. However, this is speculation.
The earthquakes could as well be related to some other (known or unknown) process, e.g. gravity-induced adjustments that respond to pressure changes and occur within previously ruptured areas of the crust beneath the island.
The next days or weeks will show what happens next.
Tremor continues to rise (now at 13), from the webcam image, it seems a lava flow is starting to issue from the SE fracture. All indicators point towards we are having the 2nd paroxysm in 2012 during the next hours! The volcanic tremor is now steeply rising (at 8) and vigorous strombolian activity can be seen on the various webcams, possibly a lava flow has started as well.
While strombolian activity continues from the New SE crater of Etna volcano, volcanic tremor has started to rise, suggesting a new paroxysm could be in the making in the next hours, although it is still early to be certain. The photo (left) from Boris Behncke was taken during the night of 7-8 February 2012, when the continuing strombolian activity of the New Southeast Crater on Etna was finally widely visible, after about one week of essentially bad weather. Some explosions threw incandescent lava bombs outside the crater, although most were rather weak and all material fell back into the crater.
This is a view of one of the stronger explosions observed on the late evening of 7 February 2012, taken from Trecastagni village on the southeast flank of Etna. The activity continued, sometimes vigorously, sometimes more subdued, through the night and morning of 8 February.
President Barack Obama pushed drilling for gas in shale rock and support for cleaner energy sources to boost the economy in his final State of the Union address before facing U.S. voters in November.
Hydraulic fracturing, the process of injecting water, sand and chemicals underground to free gas trapped in rock, could create more than 600,000 jobs by the end of the decade, Obama said yesterday. The process, called fracking, is among a list of energy policies Obama said would fuel economic growth.
“We have a supply of natural gas that can last America nearly 100 years, and my administration will take every possible action to safely develop this energy,” Obama said.
Obama reiterated support for conservation and cleaner sources of power and pledged more oil drilling as part of an ‘all-out, all-of-the-above” policy “that’s cleaner, cheaper, and full of new jobs.” He said domestic energy production is at an eight-year high and imports of foreign oil were declining, prompting criticism from Republicans.
“It’s just a blind accident, if in fact we are producing more oil or natural gas than in previous years, because it’s not because of any of his efforts,” Representative Darrell Issa, a California Republican and head of the House Oversight and Government Reform Committee, said after the speech.
YouTube link to State of the Union address at the point of natural gas discussion.
Proposed Plan – Compare to the image to the left.
December 27, 2011 - According to the National Institute of Astronomical and Geophysical Research, tremors were reported on Monday evening near Lake Nasser, south of Aswan. The population of the High Dam city barely noticed the quake, however, the tremors were felt by people in the desert regions, several tens of kilometers south of Aswan. According to scientists, the epicenter was located at a depth of two kilometers. This area was once considered a seismically hazardous area, but over the last few decades there had not been a single tremor.
The largest earthquake was said to be measured at a magnitude of 4.2.