Volcanoes
S


Bizarro Earth

USGS Watching Mount St. Helen's Volcano Following Earthquake Swarm

Image
© Unknown
The United States Geological Survey is watching the Mount St. Helen's volcano closely after a series of earthquakes struck on Monday. The area around Mount St. Helen's in Washington state has been experiencing minor earthquakes since an initial quake measuring 4.3 in magnitude struck around 10:35 a.m. local time, according to the USGS. Since that first quake, several smaller aftershocks were registered ranging between 1.0 and 2.8 in magnitude.

All of these earthquakes were centered in an area approximately five to six miles north of the Mount St. Helen's crater near the Johnston Ridge Observatory. The quakes were registered at depths between 1.7 and 3.7 miles. In total, at least 12 small earthquakes were registered in the area since the first quake on Monday.

This series of small earthquakes occurring in approximately the same location over a short period of time is known as an earthquake swarm. According to the Global Volcanic Earthquake Swarm Database earthquake swarms are especially common around volcanoes and are often reliable methods of predicting an eruption but the Alaska Volcano Observatory website offered that there may be no need for alarm. The AVO website explained that while earthquake swarms may offer information that a volcano is becoming restless, they are not necessarily indicators of a pending eruption. According to the AVO, "Most seismic swarms are not precursors to eruptions."

Attention

US: 4.3 Magnitude Earthquake Hits Near Mt. St. Helens

A 4.3 earthquake hit the Mt. St. Helens area about 10:35 a.m. Monday, followed by 30 aftershocks, according to a USGS seismologist.


USGS Seismologist Seth Moran told KGW the quake was centered near the Johnston Ridge Observatory, and registered on seismic devices as far away as Mt. Rainier and at Timberline Lodge.

Moran said the seismic event lasted about three to five seconds, and shaking from the quake lasted up to three minutes. He said there were at least 30 aftershocks.

USGS data on the 4.3quake

The 4.3 quake (pictured on the seismograph), originally rated as only a 3.3 magnitude event, happened at 10:35 a.m., about six miles north and northwest of the volcano and about three miles deep.

Arrow Up

Hawaii: Lava lake at Halemaumau crater rising gradually, could spill out to crater floor

Image
The lava lake at Kilauea's Halemaumau crater has been rising gradually in the last few months.

Volcanologists don't know what the significance of the rise is. It's possible that the lava could spill out of the pit and on to the crater floor, though this might take months to happen.

The Hawaii Tribune-Herald reported the observatory's seismologists are also watching an increased number of earthquakes in the upper east rift zone.

Hawaiian Volcanoes Observatory scientist-in-charge Jim Kauahikaua says the increase in seismicity somewhat resembled the prelude to a brief June 2007 eruption in a remote section of Hawaii Volcanoes National Park. But there have also been several similar seismic episodes when nothing happened.

Kilauea is the world's longest continually erupting volcano. The east rift zone began erupting in 1983.

Radar

US: Quakes hit Mt. St. Helens, rattle Portland area

Image
Portland, Oregon - Two earthquakes hit the Mount St. Helens area Monday morning, and one was strong enough to be felt in the Portland-Vancouver area.

KATU received many reports from viewers in the Portland area who said they felt the 10:35 a.m. temblor.

The initial quake measured 3.5 and was followed by a 2.5., but then the first quake was re-evaluated as a 4.3 - a fairly robust temblor. A 2.3 aftershock struck just before noon.

Quakes are now measured on a "magnitude scale" instead of the Richter Scale, according to KATU News Meteorologist Dave Salesky.

Radar

Earth opening up: Erupting volcanic vents found in Antarctic waters

Image
© National Oceanography Centre.One of the new deep sea vents.
British researchers say the discovery of deep-sea volcanic vents in the Antarctic's Southern Ocean suggests they're more common than previously thought.

Deep-sea vents are hot springs on the seafloor, where mineral-rich water nourishes colonies of microbes and animals.

Around 250 such vents have been discovered worldwide in the three decades since scientists first encountered them in the Pacific. Most have been found on a chain of undersea volcanoes called the mid-ocean ridge but very few are known in the Antarctic, a release from the U.K. National Oceanography Center said Monday.

Bizarro Earth

More Deep-Sea Vents Discovered

Deep Sea Vents
© NOC/SOESPreviously unknown deep-sea volcanic vents have been discovered in the Southern Ocean.
Scientists aboard the Royal Research Ship James Cook have discovered a new set of deep-sea volcanic vents in the chilly waters of the Southern Ocean. The discovery is the fourth made by the research team in three years, which suggests that deep-sea vents may be more common in our oceans than previously thought.

Using an underwater camera system, the researchers saw slender mineral spires three metres tall, with shimmering hot water gushing from their peaks, and gossamer-like white mats of bacteria coating their sides. The vents are at a depth of 520 metres in a newly-discovered seafloor crater close to the South Sandwich Islands, a remote group of islands around 500 kilometres south-east of South Georgia.

"When we caught the first glimpse of the vents, the excitement was almost overwhelming," says Leigh Marsh, a University of Southampton PhD student who was on scientific watch at the time of the discovery.

Deep-sea vents are hot springs on the seafloor, where mineral-rich water nourishes lush colonies of microbes and deep-sea animals. In the three decades since scientists first encountered vents in the Pacific, around 250 have been discovered worldwide. Most have been found on a chain of undersea volcanoes called the mid-ocean ridge, however, and very few are known in the Antarctic.

Bizarro Earth

US: Earthquake Magnitude 4.3 - Mount St. Helen's Area

Image
© USGS
Date-Time:
Monday, February 14, 2011 at 18:35:25 UTC

Monday, February 14, 2011 at 10:35:25 AM at epicenter

Time of Earthquake in other Time Zones

Location:
46.279°N, 122.215°W

Depth:
5 km (3.1 miles) set by location program

Region:
MOUNT ST. HELENS AREA, WASHINGTON

Distances:
9 km (6 miles) NNW (343°) from Mount St. Helens Volcano, WA

31 km (20 miles) S (171°) from Morton, WA

35 km (22 miles) SE (143°) from Mossyrock, WA

59 km (37 miles) ENE (75°) from Longview, WA

78 km (48 miles) NNE (23°) from Vancouver, WA

Bizarro Earth

Earthquake Swarm Just Part of New Kilauea Activity

Hawaii Volcanoes National Park - Scientists at the Hawaiian Volcano Observatory on the Big Island of Hawaii are looking at a swarm of small earthquakes that shook Kilauea Volcano last week.

There were at least 42 earthquakes in the area within a 24 hour period that started Thursday. Geophysicists said while the temblors have diminished, they are another clue in what may come next at the world's most active volcano.

"Kilauea's summit has been extending, meaning that more magma is coming up to the summit than is going out to the east rift zone," said Jim Kauahikaua, the observatory's scientist in charge. That means there's move lava underground that's headed toward the actual Kilauea caldera, rather than the zone where most of the activity has been in the volcano's 28 year long eruption.

According to Kauahikaua, the extension of the crater has been going on for a few months.

"This extension of the summit is also reflected in the rise in lava in the Halemaumau vent," he said.

"All of them are indications that pressure is increasing in the magma chamber below the summit."

Hourglass

Huge volcano under Yellowstone Park rising

Image
© National Park ServiceHydrothermal fluids, just like the ones shooting from Old Faithful, could be pushing up the Yellowstone supervolcano.
It's building quickly, but that doesn't mean doomsday eruption is imminent.

The huge volcano under Yellowstone National Park has been rising at an unprecedented rate during the past several years, according to a new study.

In the ancient past, the Yellowstone volcano produced some of the biggest-known continental eruptions, but the recent rising doesn't mean another doomsday eruption is looming, scientists say.

The recent rising is unprecedented for Yellowstone's caldera - the cauldron-shaped part of the volcano - but it's not uncommon for other volcanoes around the world. The new study has simply revealed a more active caldera at Yellowstone than scientists realized.

Binoculars

Volcano alert on Iceland

Image
© ReutersA column of steam and ash rises out of an erupting volcano near Eyjafjallajokull.
Another volcano could be about to erupt on Iceland, threatening to spew out a blanket of dust that would dwarf last year's eruption and ground hundreds more passenger flights.

Geologists say there is a high risk of the island's second-largest volcano Bárdarbunga erupting after an increase in the number of earthquakes around it.

Pall Einarsson, a professor of geophysics at the University of Iceland, says the increased activity provides "good reason to worry". The sustained tremors to the north-east of the remote volcano range are the strongest recorded in recent times and there was "no doubt' the lava was rising.