volcanic eruption

Submarine Axial volcano erupts near Oregon

Researchers at the Oregon State University had a surprise when they went to the Axial seamount volcano located about 230 miles off the Oregon coast. Last year they had left instruments to record volcanic activity. When they returned, they found the instruments buried in lava.

Axial1

The Axial volcano is located on the Juan de Fuca plate near Oregon’s coast. In a previous post I said this is the area Where the Next Big American Earthquake and Tsunami Might Occur.

According to the news release from Oregon State University:

What makes the event so intriguing is that the scientists had forecast the eruption starting five years ago – the first successful forecast of an undersea volcano.

When Axial erupted in 1998, the floor of the caldera suddenly subsided or deflated by 3.2 meters (10.5 feet) as magma was removed from underground to erupt at the surface. The scientists estimated that the volcano would be ready to erupt again when re-inflation pushed the caldera floor back up to its 1998 level.

The discovery of the new eruption came on July 28, when Chadwick, Nooner and University of Washington colleagues Dave Butterfield and Marvin Lilley led an expedition to Axial aboard the R/V Atlantis, operated by the Woods Hole Oceanographic Institution. Using Jason, a remotely operated robotic vehicle (ROV), they discovered a new lava flow on the seafloor that was not present a year ago.

This latest Axial eruption caused the caldera floor to subside by more than two meters (six feet). The scientists will be measuring the rate of magma inflation over the next few years to see if they can successfully forecast the next event.

According to NOAA:

Axial Volcano rises 700 meters above the mean level of the ridge crest and is the most magmatically robust and seismically active site on the Juan de Fuca Ridge between the Blanco Fracture Zone and the Cobb offset. It represents the product of intense volcanic activity from the Cobb-Eikelberg hotspot juxtaposed on the extensional field of the spreading center. Axial Volcano was first studied in the late 1970s and then mapped in greater detail by NOAA/VENTS with SeaBeam in the early 1980s. Following the initial discovery of venting in the northern portion of the caldera in 1983, a concentrated mapping and sampling effort was made in the mid-late 1980s.The summit of Axial Volcano is marked by an unusual rectangular shaped caldera (3 x 8 km) that lies between the two rift zones. The caldera is defined on three sides by a boundary fault of up to 150 m relief. Hydrothermal vents colonized with biological communities are located near the caldera fault or along the rift zones.

 

Katla volcano in Iceland may be priming to erupt

The Katla volcano located under the Mýrdalsjökull glacier in southern Iceland has experienced a swarm of earthquakes lately. These earthquakes are more concentrated than those that occurred last year and may pre-stage an eruption. The Katla volcano is just east of, and much larger than the Eyjafjallajokull volcano which erupted last year and spewed ash that disrupted air travel throughout Europe. The Katla volcano erupts about every 100 years. The last eruption was in 1918.

katla

 From the Volcanism Blog:

A possible small eruption under the Mýrdalsjökull ice cap in south Iceland has produced a surge of glacial meltwater, a jökulhlaup, which has caused flooding and cut the main road through the area. A bridge has been swept away, and local evacuations are apparently taking place.

That was just a volcanic burb.

For more background, see my post: Geologic Setting of Icelandic Volcanoes.

See also:

Iceland volcano and its effect on life Photos for photos of last year’s eruption of the Eyjafjallajokull volcano.

Yellowstone Super Volcano Update

In a previous post I described the volcanic region of Yellowstone National Park and its history of volcanic eruptions. The Yellowstone super volcano is the youngest of a series of volcanoes that have erupted over the past 17 million years. During the last two million years, ash from each of three eruptions covered nearly half of the United States. Yellowstone is called a super volcano because its eruptions fall in the maximum range for explosiveness and volume of material ejected.

New research from the University of Utah shows that the volcanic plume of molten rock under Yellowstone, which would feed future eruptions, is bigger than previously thought.

A study in 2009, using seismic waves from earthquakes in the area estimated that the volcanic plume showed that “molten rock dips downward from Yellowstone at an angle of 60 degrees and extends 150 miles west-northwest to a point at least 410 miles under the Montana-Idaho border.”

The new study, using electrical conductivity measurements “shows the conductive part of the plume dipping more gently, at an angle of perhaps 40 degrees to the west, and extending perhaps 400 miles from east to west. The geoelectric image can ‘see’ only 200 miles deep.”

“The lesser tilt of the geoelectric plume image raises the possibility that the seismically imaged plume, shaped somewhat like a tilted tornado, may be enveloped by a broader, underground sheath of partly molten rock and liquids,” say the researchers. Although the research says nothing about when another eruption could occur, it implies that there is a potential for a very large, super eruption.

This research will be published in Geophysical Research Letters in a few weeks. Meanwhile, you can see more details and images in the press release here.