A lot happened while we were down. Sunspot 1402 decided to show its strength as it crossed over the visible corona. From the start it began shooting out M class flares, and just as it was leaving it did the same. The strongest flare it released was an X5 class flare, which produced a large CME that mostly hit Earth. On top of several other C and M class flares, the magnetic field has had to work over time on certain occasions as of late.
The volcanic situation is interesting as always, with a few new candidates appearing on the scene, with a few old timers like Etna continuing on and on.
The largest earthquake we’ve seen since we’ve been gone was a 7.4 magnitude quake that struck Mexico on the 20th, following a 6.9 that struck Japan just a few days earlier, and prior to a 6.6 that struck PNG late on the 21st. The 188 day theory did not hold true, unfortunately. The idea was that there was a megaquake separated by a 7 mag quake in this pattern, since February 27, 2010. While we did have some 6 magnitude action and a 7.4, it still isn’t enough to say that this cycle held out. I think that it may be indicative of a pattern of movement roughly every 6 months or so, but rounding it down to the day, or hour, is likely to yield no real results. That’s all at present. The equinox has come, and now shall the colours of 2012 really start to come through.
(Activity update written by scientists at the U.S. Geological Survey’s Hawaiian Volcano Observatory.)
A lava lake present within the Halema’uma’u Overlook vent during the past week resulted in night-time glow that was visible from the Jaggar Museum overlook. The lake, which is normally about 90–115 m (295–377 ft) below the floor of Halema’uma’u Crater and visible by HVO`s Webcam, rose and fell slightly during the week in response to a series of large deflation-inflation cycles.
On Kilauea’s east rift zone, surface lava flows were active on the pali and upper coastal plain, in Royal Gardens subdivision, over the past week. As of Thursday, March 22, the flows were still more than 2 km (1.2 miles) from the coast, and there was no active ocean entry.
Two earthquakes beneath Hawai’i Island were reported felt this past week. A magnitude-2.7 earthquake occurred at 3:42 p.m., HST, on Monday, March 19, 2012, and was located 4 km (2 mi) southeast of Pu’ulena Crater at a depth of 2 km (1 mi). A magnitude-3.7 earthquake occurred at 00:04 a.m. (4 minutes after midnight) on Thursday, March 22, and was located 40 km (25 mi) west and offshore of Kailua-Kona at a depth of 33 km (21 miles).
“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.
Most fish in the lake have died and occasionally dead birds are found at the shore. No other signs of a possible volcanic awakening were detected at the moment. The ph level of the water is still at normal levels 7-8, and there is no sulfur smell. Also, no significant seismic activity has been detected. Nevertheless, PVMBG has now placed the volcano at alert level 2 (“watch”, on a scale of 1-4) and recommends to stay away at least 500 m from the lake shore.
The last eruptions of Galunggnug was a small phreatic explosion in 1984, and the major destructive eruption in 1982-83, which produced violent explosions with ash columns reaching 20 km height, pyroclastic flows and large lahars. The eruption destroyed an older lava lake, killed many people and displaced up to 35,000.
The eruption is infamous for the aircraft accident on 24 June 1982: a British Airways Boeing 747 with 262 people on board flew through the ash plume and had to make an emergency descent after the ash caused all 4 engines to fail; fortunately, the plane could land safely.
The present-day crater lake (Danau kawah Galunggung) has a diameter of 1000 m and is 11 m deep and contains a volume of about 8 million m3 of water. In the middle of the lake, a small 250 x 165 m diameter scoria cone which was produced during the final staged of the 1982-83 eruption rises to 30 m elevation.
A main hazard of the volcano are phreatic and phreatomagmatic eruptions capable of draining the lake and producing mud flows.
Mount Kanlaon, an active volcano, has been declared temporarily closed to mountaineers after large cracks believed to have been caused by Monday’s 6.9-magnitude earthquake were observed at its crater and land surfaces, a local official said Friday.
Kanlaon straddles the provinces of Negros Occidental and Negros Oriental. It has an elevation of 2,435 meters (7,989 feet) and a base diameter of 30 kilometers.
Cecil Cañada, Mt. Kanlaon Natural Park (MKNP) superintendent, said at least three 50-meter long cracks have been noted near the crater, while other cracks and a landslide have been noted within the MKNP.
A landslide was also seen at the Margaha Valley, the old crater of the volcano, he added.
An assessment was conducted by accredited trained guides and members of the rescue group based in Guintubdan, La Carlota City, in coordination with the MKNP Eco-tourism Officer and Biologist Angelo Bibar, Cañada said.
Their report revealed that some portions of the volcano’s crater were affected, and land surfaces had cracks and evidences of landslides, he said.
Cañada also maintained that the aftershocks from Monday’s earthquake and occasional heavy rainfall could pose danger to the life of mountain trekkers and tourists in the park.
The Philippine Institute of Volcanology and Seismology has been informed of the quake damage to the volcano and they were trying to arrange for an aerial survey of the area, he added.
However, it is difficult to get a helicopter as they are being used for relief operations in Negros Oriental, Cañada said.
The volcano continues to be under observation amid the continuing aftershocks, after a magnitude 6.7 quake rocked the area on February 06.
A restless volcano in northern Indonesia erupted Friday, spewing clouds of ash as high as 2 kilometers into the sky, the country’s National Disaster Management Agency said.
The authorities are warning residents to stay away from the volcano, Mt. Lokon, in North Sulawesi, said Sutopo Purwo Nugroho, a spokesman for the disaster management agency.
A 2.5 kilometer exclusion zone had already been set up around Mt. Lokon, which had been showing signs of activity in recent days.
A series of eruptions by Mt. Lokon in July prompted the evacuation of thousands of local residents. The volcano also erupted in October and December.
Indonesia is located on the “Ring of Fire,” an arc of fault lines circling the Pacific Basin that is prone to frequent earthquakes and volcanic eruptions.
Mount Lokon, together with Mount Empung, is a twin volcano (2.2 km/1.4 mi apart) in the northern Sulawesi, Indonesia, roughly 10 km (6 mi) south of Manado. Both rise above the Tondano plain and are among active volcanoes of Sulawesi. Mount Lokon has a flat and craterless top.
Lokon formed during a period of andesitic volcanism on ring fractures resulting from the Tondano caldera’s early to mid-Pleistocene collapse. Recently-erupted material remains andesitic in composition and consists of ash plumes and, less commonly, pyroclastic flows and lava domes.
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.
A slight increase in activity of Semeru volcano’s activity has been observed by the Indonesian Geological Survey in recent weeks and its alert level was raised to 3 (out of 4, “watch”) on 3 February 2012, after it had been on level 2 since 16 July 2009.
Only small to moderate eruptions had been occurring over most of the past year. Between 29 December and 15 January, 8 explosions were counted which produced ash clouds up to 600 m high. One explosion threw incandescent bombs to a distance of 300 m from the Jonggring Seloko crater. During 15-29 Jan, only weak explosions were recorded and a small steam and ash plume rising 25-50m.
Between 30 and 31 Jan, 5 explosions were recorded. They produced incandescent fallout in up to 400 m distance. On 02 February, 07:47 local time, a stronger explosion produced incandescent bombs that reached 750 m distance and caused a small avalanche of blocks rolling down a distance of up to 2.5 km ( no pyroclastic flows). The heightened activity triggered the raise in alert level the following day.
At its present level, PVMBG recommends to stay away at least 4 km from the summit on the SE side of the volcano and climbers are advised not to approach the Jonggring Seloko crater less than 1 km.
As of 6 February, no significant changes to its activity have been reported by our correspondent.
Alaskan scientists are monitoring a massive volcano that may erupt, sending an ash cloud into the sky that could cause a headache to international air travel.
The volcano, known as Mount Cleveland, is located on a remote island in the Aleutian Islands approximately 1,000 miles southwest of Anchorage. The nearest town to the volcano is about 70 miles away.
As of Friday, the Alaska Volcano Observatory continued to keep their alert status for the Cleveland Volcano at Code Orange, which is one step below the highest alert level. The observatory bumped the alert status earlier this week from yellow to orange.
According to the group, “Satellite observations throughout the week suggest that eruptive activity at Cleveland Volcano has slowed or paused”, but concern still remains “for intermittent, sudden explosions of blocks and ash to occur at any time, and ash clouds exceeding 20,000 feet above sea level may develop.”
The volcanic activity has many in the airline industry concerned due to volcanic ash that could threaten international flights.
About 90% of air freight from Asia to Europe and North America flies over Alaska air space, including hundreds of flights totaling more than 20,000 passengers that fly through Anchorage’s air space daily, according to CNN.
Airline experts say that a significant volcanic eruption could lead to hundreds of flights being rerouted or ultimately cancelled.
An eruption from the Cleveland Volcano could bring back memories of last year’s Grimsvotn Volcano as well as the Eyjafjallajokull Volcano that erupted in 2010 when a giant ash plume grounded millions of travelers worldwide. Both volcanoes are located in Iceland.