Merapi Update for 11/4/2010: The eruption worsens

The new eruptive phase at Merapi appears to be getting worse - and from the sound of it, the volcanologists at the Centre for Volcanology and Geological Hazard Mitigation aren't sure what to expect. Surono, the head of the Centre, described the volcano as entering an "even worse stage" and that "we have no idea what's happening now." Those are never good words to hear from the volcanologists on the ground, but shows how unpredictable volcanoes can be. A new dome was noticed on the volcano on Wednesday after the latest large explosion (video), but it is unclear how long it will survive or how much pressure the extruding lava might take from the underlying magma.

The images of the eruption are impressive to say the least (see below). The eruptive plume indicates that there is a lot of pressure in the volcanic conduit and when you combine this with periodic collapses of the dome in the main crater that are producing pyroclastic flows (see below), the combination is about as bad as you can muster with a composite volcano. The ash plume reached over 6 km / 20,000 feet yesterday with noticeable ash fall as far afield from the volcano ash 240 km. The rain on the slopes of the volcano has also remobilized the newly-erupted volcanic tephra (indonesian) to produce lahars down some of the volcano's drainages.

The eruptive plume from Merapi on November 4, 2010.

The ramifications of the eruption are becoming more apparent as well. The refugee shelters for evacuees are being moved to further away from the volcano due to Merapi's increasing activity. Meanwhile, more airspace over Indonesia is being closed due to the ash hazard presented by the eruptions. The death toll from the eruption has now reached at least 44, although many deaths might have been prevented if people living on the slopes of Merapi heeded the government's initial warnings. Upwards of 75,000 people have now been evacuated from the extended danger zone around the volcano.

You can follow some of the action on the ground in Indonesia via Twitter as well: @jalinmerapi_en. I'll post more updates on this post as well as the news merits.


  • I'm linking to this story from the Herald Sun mostly for its over-the-top headline: "Volcano's explosive rain of fire". Nothing like a headline that offers no information!
  • Check out this interview with our own James Reynolds over on the NYT's Dot Earth.
  • Some clear talking from Indonesian officials about eruptions.
  • Surono from the Volcanology and Geological Disaster Mitigation Agency now says this eruption of Merapi is the worst in over 140 years. Death toll for the 1872 eruption is off. (Thanks again to Boris Behncke for finding the Jakarta Globe links). 
  • Evacuees up to 90,000.
  • Apparently there has been a big new eruption at Merapi, topping out at 16 km / 55,000 feet {h/t to MRK}
  • Pyroclastic flow hits town 15 km from the volcano.
  • {Special thanks, as usual, to all the Eruptions readers who provided links for this post.}

    Top left: The plume from Merapi captured by a nearby aircraft on November 4, 2010.

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