Mt. Hakone Outside Tokyo Erupts

6/30/2015 — After 800 years of silence , Mount Hakone Erupts in South Japan — 45 miles from Tokyo


After 800 years of silence, the long dormant Mount Hakone Volcano has finally awoken.

This volcano hasn’t erupted since the middle ages, 1170AD !

New flyover released today (June 30, 2015):

News report here:

Video report here:

Over the past two months, warning signs have been showing around the ancient volcano, which is located just 45 miles Southwest of downtown Tokyo.

Over the past 5 weeks (since Mid May 2015) the ground rose several inches, and began steaming around the countryside spanning multiple miles.

hakone volcano close up a

hakone volcano close up

Here is the previous video from almost exactly 1 month ago to show the steaming as it built up to this new eruption.

-Update 1 hour after posting this article-

Current image of Hakone resort area 【画像取得年月日 – 2015/06/30-17:00 – 】 seen via the webcam here:


Now breaking news on Reuters :

Small volcanic eruption closes parts of resort near Tokyo

TOKYO (Reuters) – A small volcanic eruption at a Japanese hot springs resort not far from Tokyo prompted authorities on Tuesday to further limit access to the area, warn that more eruptions were possible and urge a handful of people to evacuate.

Japan, one of the world’s most seismically active nations, has suffered a recent spate of eruptions, including one that forced the evacuation of a southern island. In September, 63 people died when a peak crowded with hikers suddenly erupted.

Volcanic ash was spat from a valley on Mount Hakone, which has been belching out unusual amounts of steam in recent months, forcing officials to close part of the resort at the start of the spring tourist season.

There were no reports of injury or damage, and roughly 40 people were urged to evacuate.

Japan’s Meteorological Agency raised the warning level on the mountain to 3 from 2, closing a broader area, and an agency official said activity in the area, some 80 km (50 miles) west of Tokyo, seemed to have risen “to a new level”.

“It was an extremely small scale eruption, but there is the chance of a larger one that could affect a wider area,” he told a news conference.

Hakone is a resort famed for its hot springs and views of Mount Fuji. More than 21 million people visited in 2014, including 217,000 from overseas, the Hakone town office said on its website.

White clouds, apparently steam, billowed up from vents in the stark Owakudani, “Great Boiling Valley”, the 1,044-metre (3,425 ft) high area around a crater created during an eruption of Mount Hakone 3,000 years ago.

Predicting the scale of any eruption is hard because the mountain last erupted 800 years ago, said volcanologist Toshitsugu Fujii, an emeritus professor of Tokyo University.

“If hot water or magma becomes involved, it could explode at a deeper level, and there would probably be very little warning,” he said.

“Things are now taking place at a shallow level and probably it won’t go that far. But you can’t say when that might change.”

Fujii did say it was highly unlikely that Hakone’s activity foretold an eruption of iconic Mount Fuji, which used to erupt every 30 years but has been silent since 1707.

A catastrophic eruption of the 3,776-metre-high (12,390-ft-) peak could rain some 10 cm of ash on Tokyo, located 100 km to the northeast.”

Here is a translation from a Spanish source:

30/06/2015 (June 30, 2015):

Raise alert level after a small eruption at a nearby volcano to Tokyo

“The Japan Meteorological Agency (JMA) today ordered to evacuate the vicinity of Mount Hakone, located about 80 kilometers southwest of Tokyo, having confirmed a small eruption in it.

Evacuate the area is in the so-called Owakudani Valley, on the slopes of the mountain, where there are two houses, eight hotels and hostels, a spa, a business and 12 houses that are rented to vacationers, and where a total lie 40 people, public broadcaster NHK reported.

On the occasion of the eruption, the JMA has high elevation alert, which consists of five levels, from step 2, it is advised not to approach the crater or access adjoining areas considered at risk, to 3, asking not to approach Mount the environment, according to the agency reported.

The agency confirmed today that the Mount recorded on the eve a small eruption after detecting new vents and ash accumulation by the volcano spits.

The new alert level prohibits access to a perimeter of one kilometer around the Owakudani Valley, a popular spa area on the slopes of Hakone that is under close surveillance since May, when the JMA detected the possibility of an eruption by volcanic earthquakes increase.

The agency has stressed the danger of landslides and the possibility of ash clouds spewed by the volcano in the Owakudani.


Icelandic Volcano Update

Holuhraun Eruption in Iceland Still Going Strong

Part of the Holuhraun eruption in Iceland, seen on October 21, 2014. Photo by Milan Nykodym / Flickr.

If you can believe it, we’re now in the fourth month for the Icelandic eruption that started north of the Bárðarbunga caldera in Iceland. The world watched and waited for this eruption after weeks of intense earthquakes, but since the eruption began in late August, we’ve had a nearly constant stream of basaltic magma eruption from the fissures in the Holuhraun lava fields between Bárðarbunga and Askja. This eruption has drifted from the headlines because the eruptive activity itself has been fairly tame — no giant ash plumes to disrupt air travel across Europe, but instead just a steady flow of lava creating a new lava field that covers over 72 square kilometers (~17,700 acres; see below). You can watch some great slow-motion footage of the lava erupting at one of the main vents, taken October 27 by Karl Neusinger – it really shows the constant influx of lava from below that creates the impressive lava flow field. This eruption at Holuhraun now has the distinction of being the largest (by volume) in Iceland since the massive 1783-4 eruption of Laki (although Holuhraun trails Laki by “only” 16 cubic kilometers of lava!)

The Holuhraun lava field (shown in white outline) and the active vent seen by Landsat 8 on November 16, 2014. Image by University of Iceland Institute of Earth Sciences / IMO.

The biggest hazard produced by the eruption so far has been to the air quality in Iceland, where the sulfur dioxide emissions from such a constant and vigorous basaltic eruption has meant that people have been required to stay indoors during much of the summer and fall months on the island nation. Analyses of the rainwater in Iceland over the past months show that as much as 40% of the rain that has fallen is acidic (pH <7) with some rain as low as pH 3.5 (as John Stevenson put it, that’s like grapefruit juice rain).

At Bárðarbunga, the floor of the caldera has continued to subside during this whole eruption without much signs that any eruptions have occurred under the ice that fills the caldera (however, the increased heat from the geothermal system may have melted some of that ice). That, in itself, is interesting and tells us something about how some of these Icelandic calderas can form. Instead of the catastrophic events that many people envision for caldera formation (e.g., Crater Lake), these are slow subsidence events that might takes months to occur. Calderas at other large shield volcanoes have also formed in this fashion, but to be able to measure the motion so precisely is a great scientific bonanza. Large earthquakes are still occurring under the caldera as well, with a M5.4 happening just yesterday (November 18).

The NASA Earth Observatory recently posted an image of the plume from the Holuhraun fissure that shows how the plume itself might interact with the clouds around the eruption. More likely than not, eruption plumes can play a role in cloud formation and distribution around a volcano.



Hawaii, Iceland Volcanic activity

Eruption Update: New Fissure Eruption Starts Closer to Vatnajökull in Iceland, Kilauea Lava Flow Threatens Homes

Lava fountaining in the second fissures in the Holuhraun lava field, Iceland, seen on September 4, 2014. Photo by Image from  Jonni Productions video.

Two updates for today, dominated by action at the two most famous hotspots on the planet:


A new fissure started erupting this morning to the south of the current activity in the Holuhraun lava fields in Iceland. These two new fissures are closer to the Vatnajökull ice cap (just 2 km north of its edge), so concern is growing larger than the eruption will start happening subglacially, potentially causing jökulhlaups (glacial outburst floods) as the lava erupts under the ice. The Icelandic Meteorological Office is also reporting that the cauldron (depression) in Dyngjujökull, the northern part of the ice cap, is getting larger and more pronounced, both of which are signs that more heat is being felt at the bottom of the ice (possibly caused by eruptions under the ~300-350 meters of ice). Check out these images of the cauldron on the ice surface. The most serious ramification is the potential for more explosive style of eruption if water can mix with the lava.

So far, the vigor of the eruption at the new fissures is lower than the other active fissures, where lava fountains (see above) are reaching over 100 meters into the air. Be sure to check out these great images of the lava fountaining, spatter cones and lava flows of the larger fissure field. The older lava flow field now covers just over 10 square kilometers. Watch this video to see what it’s like to get up close and personal with the lava flows right now.


The steam plume from the eruption is reaching 4.5 km (15,000 feet) and the sulfur dioxide plume is beginning to spread beyond the region right around Iceland. Changes in the weather patterns around the island suggest that the plume may spread enough to reach Europe, although the only possible ramifications of that might be some sulfur odor across the British Isles.


Lava flows approaching KKK Homesteads on Kilauea's slopes, seen on September 3, 2014. Photo by Hawaii Volcano Observatory / USGS.

Meanwhile, in Hawai’i, lava flows are threatening homes on the slopes of Kilauea (see above). The USGS has raised the alert status at Kilauea to its highest – Warning – after lava flows exploiting a ground crack moved downslope and re-emerged near the Kaohe Homesteads. This lava flow was able to move so much further downslope thanks to the insulating nature of the ground crack, keeping the lava hot enough to flow longer and faster. At the current rates of flow, the lava could reach the Homesteads in 5-7 days if it continues to exploit the ground cracks. Currently, the lava flows are burning their way through the forested lands on the flank of Kilauea. The Hawaii Volcano Observatory has an excellent collection of images of the lava flows, showing how it is advancing towards the homesteads. Although these lava flows aren’t a hazard for people as such, previous lava flows have destroyed entire communities on the slopes of the volcano.


Costa Rican VOlcano Poas Eruption

Eruption Update for February 28, 2014: Poás,

The opening salvo of the eruption at Poas in Costa Rica, captured on the crater webcam. Image: OVSICORI webcam capture.

The opening salvo of the eruption at Poás in Costa Rica, captured on the crater webcam. Image: OVSICORI webcam capture.

Costa Rica

Earlier this week, Poás in Costa Rica had a small eruption likely related to water flashing to steam in the heating crater lake area. This eruption ended up being the largest so far in 2014, but these types of explosion are fairly common at the Costa Rican volcano. That being said, María Martínez Cruz (OVSICORI) said that the size of this eruption, with a plume that reached 300-meters, is not too common at Poás. This could suggest that more heat is being fed into the upper reaches of the volcano. The webcam at Poás captured the eruption as it occurred, spreading ash mainly within the crater area. If check out the webcam at night, you can see some intense incandesce that betrays the magma just beneath the surface at the volcano. Not surprisingly, the volcano is off-limits to tourists.


Volcanic Activity: Etna & Sinabung

Eruption Update for November 24, 2013: Sinabung and Etna

Webcam capture of the November 23, 2013 eruption of Etna in Italy. Image: @Culturevolcan / Twitter

Quick post as I get ready for our Thanksgiving Week trip to the great white north (also known as Chicago):


The PVMBG has moved Sinabung up to its highest alert after a series of powerful explosions overnight reaching 2-8 km (6,500-25,000 feet). In the region around the volcano, over 12,000 people in over 17 villages have been evacuated due to the increasingly hazardous activity at the volcano. Right now, it seems like no one is quite sure what is going to come next — all that we know is that activity has been on the increase over the last month. Although the ash from these explosions have cause some flight disruptions, it is not yet a threat to people living in the regional capitol, roughly 50 kilometers (31 miles) away.


Meanwhile in Italy, Etna had yet another paroxysm, this time less than a week since its last one. This one produced a significant ash plume with lava fountaining, but little-to-no lava flow activity. One of the more impressive videos I’ve seen for the eruption was one taken by hikers on Etna who had basaltic scoria rain down on them. VolcanoDiscovery also posted a time-lapse of yesterday’s eruption.


New Island in the Pacific

Eruption at Nishino-shima in the Pacific Produces a New Island

The new island of Niijima at Nishino-shima, south of Japan, seen on November 21, 2013. Image: Japan Coast Guard

Somehow as November slipped by, I missed marking the 50th anniversary of the eruption at Surtsey off the coast of Iceland. This eruption started as a submarine one that was large and sustained enough to produce a new island in the North Atlantic. These sorts of events are fairly rare. Most of the time a new volcanic island emerges, it is quickly eroded by wave action. This is due to the nature of the material that constructs those early volcanic island, that being volcanic tephra. The island is more-or-less a pile of loose debris piling up until it reaches the surface. In order for the island to have much lasting power, it needs to emerge from the sea and erupt for long enough to start producing more resistant lava flows that will keep the waves from washing away the island.

Why do I bring this up now? Well, it seems we have an eruption like Surtsey occurring in the middle of the Pacific Ocean south of Japan. A new eruption at Nishino-shima has breached the surface and started to produce a small island (see above) of black volcanic tephra. The new island (being called Niijima) still looks small, with some reports putting the island at a cozy 200 meters (650 feet) across and 20 meters (65 feet) high — likely not something that would survive for long in the rough Pacific if it only grows to this size. The plume hasn’t been noticeable (at least to me) in any satellite imagery, but that could change some now that the island is above sea level. So far, there isn’t really any hazard for people who live near the remote island, but the Japanese Meteorological Agency has warned ships not to approach the crater. You can see the action in this Japanese Coast Guard video of the eruption, along with some great images of the eruption here. The new vent is just off the shores of another small island and some of the stills included in the news report show those classic “rooster tail” eruptions (see below) that go with these Surtseyan eruptions (named after the aforementioned Iceland event).


“Rooster tails” during the eruption of Niijima at Nishino-shima in Japan, seen on November 20, 2013. Image: Japan Coast Guard.

Nishino-shima is part of a caldera within the aptly-named Volcano Island arc (part of the Izu-Bonin-Mariana volcanic arc). There are a number of caldera along the act including Nishino-shima and the more famous Ioto (Iwo-Jima). The last major eruption from Nishino-shima was exactly 40 years ago, when another small island was produced by the volcano — potentially its only eruption in the last 10,000 years. Since then, discolored water has been spotted in the vicinity, suggesting submarine eruptions or active submarine fumaroles have been going since that 1974 eruption. However, this new activity is apparently the first to break the sea’s surface since those events 40 years ago. If you need something to read, there is a fascinating article at how quickly the new island at Nishino-shima was colonized by plants and arthropods after it formed in 1974 — just shows how quickly life will colonize new land.

I did enjoy finding a news report about how Japan is eager for this island to become a permanent feature as it could expand their territorial waters in the Pacific Ocean. It might take awhile before the volcanic island can be truly declared permanent (and I’m not even sure who does that … the United Nations?) The region has been a site of some dispute with China over territorial island, so Japan has a strong interest in expanding their presence in the region. There isn’t much in the way of people in the Ogasawara Islands (Bonin Islands), but the whole region is a UNESCO natural world heritage site, so tourism is important.



Volcanoes – Etna & Sinaburg

Eruption Update for November 5, 2013: Etna and Sinabung

Etna in Italy erupting from two vents simultaneously on October 26, 2013. Image: Dr. Boris Behncke / Flickr.

Sometimes it takes as many days as the meeting to catch back up afterwards — which is clearly the case for me after GSA this year. Finally getting almost on track as we hurtle into November.

Volcano news!


So, like clockwork, right as I leave for Denver and the GSA meeting, a volcano decides to put on a show. This time it was Etna. After six months of relative quiet, the Sicilian volcano put on quite an impressive show (see above), with eruptions from two craters simultaneously: the New Southeast Crater and the Northeast Crater (see above). Both of these eruptions were explosive, producing plumes that reached a few kilometers over the volcano and spread ash across the area of eastern Sicily. At the same time, a lava flow issued from the saddle between the two crater, meaning that Etna has erupting from at least three different vents simultaneously during the October 26 eruption. Dr. Boris Behncke of the Osservatorio Etneo posted an excellent video of the action during the 10/26 paroxysm that shows the lava fountaining that occurred from the New Southeast Crater. Towards the end of the video, you can see some great examples of strombolian activity during the waning stages of the eruption from the New Southeast Crater as giant bubbles pop in the conduit of the erupting vent. Each “pop” of that bubble would send out thousands of lava bombs, and created the booming sound you can hear on the video. Dr. Behncke also posted a great sequence of images and a story behind the remnants of a former volcano observatory on Etna. Right now, only the antenna of the former building sticks out above many years of volcanic debris, but the October 26 paroxysm lava flow came with 1 meter(!) of knocking down even that last vestige of the structure. Things have settled down at Etna after this eruption, but as we all know, the volcano can ramp up quickly to a new paroxysm.



Across the world in Indonesia, Sinabung continues to produce explosive eruptions. Right now, these discrete event have been producing ash plumes that reach up to 7 km (23,000 feet) over the volcano. All of this activity at Sinabung prompted the PVMBG to raise the alert status at the volcano to its second highest setting (siaga – alert). This move increased the exclusion zone around the volcano to 3 km and ~1,300 more people have evacuated the slopes of the restless volcano. Elsewhere in Indonesia, looks like people want to add some fearmongering to the menu (as if actively erupting volcanoes weren’t enough). The IB Times has an article proclaiming “Lake Toba’s Volcanic Underbelly ‘Could Erupt at Any Time’“, snatching a poor choice of words by the president of the Indonesia Geological Experts Association, Rovicky Dwi Putrohari. The article itself sounds like an attempt by the IGEA to promote its annual conference that occurred this week — nothing like capitalizing on fear of the next eruption from a caldera to grab the media’s attention.


Submarine Eruption off Indonesia

New Submarine Eruption at Iliwerung in Indonesia

Landsat 8 OLI image of Iliwerung in Indonesia on Lembata Island, seen on August 12, 2013. The dark grey area is the volcanic complex, while the grey box marks where the new submarine eruption from the Hobal vent is likely occurring. Image: USGS/NASA.

Interesting news coming out the of the East Nusa Tenggara Province in Indonesia. An undersea volcano off of the southern coast of Lembata unexpectedly erupted over the last few days, producing strongly discolored waters and a plume (likely made dominantly of steam) that reached 2 km (6,500 feet). The latest GVP Weekly Volcanic Activity Report also mentions incandescence noted at the sea’s surface. According to news reports, the volcano is called “Mt. Hobalt”, however, in the Global Volcanism Program‘s database, no such volcano exist. There is a Hobal that is part of the larger Iliwerung complex in the right area of Lembata, so this seems to be the volcano that is erupting. This volcanic complex has been producing diffuse fumarolic activity since the beginning of the month and the PVMBG noted that seismicity has increased sharply in this area as well.  This new eruption from Hobal has prompted the PVBMG (Center for Vulcanology and Geological Disaster Mitigation) to put Hobalt on a Level II alert and warned fishermen and tourists to avoid the area. There have been some fears that this activity near the coast could produce a tsunami, but so far those fears are unfounded. This would be the first eruption from Iliwerung since 1999 and much of the eruptive activity at Iliwerung has been from Hobal since 1973. The last known subaerial eruption from Iliwerung was in 1948 (but records can be incomplete across Indonesia).


Meanwhile, the continued eruptions at Rokatenda has caused a larger-scale evacuation of the region around the volcano. Seven hundred housing units are to be constructed for people who have had to leave their homes since October 2012 due to the ongoing activity. Recently at least 6 people died from a pyroclastic flow that swept across a beach where villagers were living on the island volcano.


On the power of Volcanoes

Revamping the Volcanic Explosivity Index (Or Tiny Eruptions Need Love, Too)

Small (but still hazardous) explosive eruptions from Kilauea in 2008 might require a tweaking of the Volcanic Explosivity Index (VEI). Image: HVO/USGS.

Much of the discussion of volcanic eruptions tends to center on the big ones — those monstrous eruptions that really capture everyone’s attention, potentially plunging parts of the planet into a cool spell that could last years. Those eruptions are relatively rare, coming a few times a decade for the smaller ones and a few times a century (or longer) for the real colossal blasts. It is true that those are important events to understand, especially because humanity will need to face life after a giant eruption like Tambora or Taupo someday in the future. However, all this focus on the enormous eruptions ends up leaving those “everyday” events in the cold. Even if they are small, they can have a profound effect on local areas, especially if they are places that are highly frequented by tourists.

Some background on the scale of volcanic eruptions: The Volcanic Explosivity Index (VEI; see below) was devised as a way compare eruptions (mainly explosive eruptions) much in the same way we compare earthquake magnitude using the Richter Scale. It was developed mainly to discuss eruptions that have an impact on global climate (that is, the big eruptions). The VEI is based on the volume of volcanic tephra (debris of explosive eruptions, like ash and bombs) that the eruption produces, so VEI 0-1 eruptions produce small amounts of tephra, only ~10,000 m3 (picture a cube with ~21.5 meter / 70 foot sides) while the VEI 7-8 eruptions produce a remarkable 1,000,000,000,000 m3 (take that cube and make it 10 km / 6.2 miles on each side). A VEI 7-8 eruption is actually 10 million times more productive than a VEI 0-1, however across the Holocene (the last 10,000 years), there have been only 6 eruptions that make it into into the heady VEI 7-8 territory while there have been at least 2215 VEI 0-1 eruptions that we know of. I emphasize this idea because a VEI 0-1 eruptions leaves little to be preserved in the geologic record — maybe a mere dusting of ash or a small lava flow — so this value is minimum value for these eruptions*.


The Volcanic Explosivity Index with volumes and terminology as currently defined. Image: Table 8 from Siebert et al. (2010), Volcanoes of the World, 3rd Edition.

That being said, if you’re standing near the vent of a 0-1 explosion, well, you can still get hurt or killed. Volcanic debris is heavy and it is thrown out of the vent at high speeds, so even a small explosion can be hazardous in places where people frequent. You might notice on the VEI that these very small explosive eruptions, those under 10,000 m3 fall into the VEI 0 category, which is described as “gentle”. That is because this is where the VEI breaks down and treats all eruptions that produce small volumes of tephra (remember, explosive debris) as effusive eruptions — that is, eruptions that produce lava flows. However, this is not the case in many places. The eruption of Mayon in May 2013 was a tiny phreatic (steam-driven) explosion that was likely VEI 0 but it killed 5 climbers who were near the vent when it occurred. That would hardly be considered as “gentle”.

Similarly, in 2008, Hawaii’s Kilauea produced a series of small explosive eruptions from the Halema’uma’u summit vent and this is detailed in a recent paper by Bruce Houghton and others in Geology. These explosions only produced 10-310 m3 of tephra, but due to the close proximity of the vent to tourist attractions and roads, they could have inflicted significant damage and injury if, let’s say, a tour bus was caught in their path. Thankfully this didn’t occur in 2008. These explosions were very small strombolian- or Hawaiian-style eruptions that would likely never have been noticed in the geologic record except for the fact that the Hawaii Volcano Observatory is right there, next to Halema’uma’u, to see it all happen. Clearly, these eruptions, although technically VEI 0, were not effusive or gentle. How can we handle such events?

A revised version of the VEI to account for very small but still explosive eruptions, as suggested by Houghton and others (2013). Image: Figure 5 from Houghton and others (2013).

Houghton and others (2013) suggest we might need to tweak that VEI scale to account for smaller explosive eruptions. However, we don’t want to disrupt the definitions for VEI 1-8, so they suggest we project downward, so the 2008 eruptions at Kilauea would be VEI -2 to -4 (see right): clearly explosive, but small. The use of “gentle” and “effusive” would be jettisoned from the VEI — after all, it is an explosivity index — and instead those small strombolian and Hawaiian eruptions that would be lumped into VEI 0 could be discussed with more clarity, which is important for developing volcanic hazard assessments for highly trafficked volcanic vistas like Kilauea or Tongariro. The next challenge would be figuring out how to compare the effusive (lava flow) eruptions with the explosive eruptions, which is more of an apples and oranges issue. However, by adding negative VEI values, we can give those small explosions a little more of their due.

* Sidenote: If you do a rough estimate of the total volume over the last 10,000 years of all the VEI 0-1 eruptions (assuming 10,000 m3 per eruption, which is likely a very loose estimate), the total volume still only adds up to roughly a VEI 2-3 eruption (something like Redoubt’s 2009 eruption).


Activity at Alaska’s Pavlof Volcano

Reinvigorated Eruption at Pavlof Disrupts Air Traffic

The explosive opening phase of the Pavlof eruption, seen on May 18, 2013. The current activity at Pavlof is likely very similar to what occurred during the first days of the eruption. Image: Brandon Wilson / AVO-USGS.

The eruption at Pavlof in Alaska looks to be increasing over the past few days, according to the latest reports from the Alaska Volcano Observatory. Not since the eruption initually started has Pavlof produced ash plumes as impressive as the ones generated Tuesday and Wednesday, with estimates based on satellite imagery (which are somewhat obscured by clouds as well) and pilot observations of ~8.5 km (28,000 feet). Without clear views from the ground, it is hard to determine the exact nature of the eruption, but likely Pavlof is experiencing another bout of lava fountaining from the active crater, similar to the activity in early May. However, most terrestrial views have been obscured by clouds. The seismicity at Pavlof over the last 48 hours has been the most intense since the volcano rumbled back to like over almost two months ago, supporting the idea that the eruption has been reinvigorated into a new explosive phase. Ash fall has also been reported in communities to the southwest of Pavlof, including King Cove, 48 km (30 miles) distant.


This betrays the importance of remote sensing when it comes to volcano monitoring. Without satellite observations and seismic stations, we would know very little about this eruption at Pavlof — and it has caused some flight disruptions for airlines that service the Alaska Peninsula and Aleutians. So far, the winds have been blowing the ash out to sea rather than towards the Alaska mainland, however, if the winds were to change, more flights could see disruption as far inland as Anchorage.