This blog provides commentary on interesting geological events occurring around the world in the context of my own work. This work is, broadly, geological fluid dynamics. The events that I highlight here are those that resonate with my professional life and ideas, and my goal is to interpret them in the context of ideas I've developed in my research. The blog does not represent any particular research agenda. It is written on a personal basis and does not seek to represent the University of Illinois, where I am a professor of geology and physics. Enjoy Geology in Motion! I would be glad to be alerted to geologic events of interest to post here! I hope that this blog can provide current event materials that will make geology come alive.

Banner image is by Ludie Cochrane..

Susan Kieffer can be contacted at s1kieffer at gmail.com

Thursday, December 2, 2010

Cold Lahars Displacing People at Mount Merapi, Indonesia

Dredging in the Code River, Yogyakarta
Photo from here.
Eruptions at Mount Merapi, discussed herehere, and here before in this blog, produced ash and other debris that sits atop the mountain awaiting the monsoon rains. Those rains have arrived; the wet monsoon season in Indonesia lasts from November through March. For weeks muddy torrents have been flowing down from the mountain. On November 30 an apparently big one, reported to be up to 2 meters deep, arrived. According to the Nov. 30 edition of the JakartaGlobe, thousands of residents were forced to evacuate. These muddy flows of volcanic materials are termed "lahars", and they can be either hot or cold depending on the timing of the volcanic activity and the weather.

The lahars flow down the channel of the Code River, which flows through the center of Yogyakarta.  The river has been channelized to control the path of the lahars, a historic danger from Merapi. Sandbags up to 1 meter high help control the flows, but authorities have warned residents that these temporary levees will not contain the large flows that are likely to occur.  Surono, the head of the Volcanology and Geological Disaster Mitigation Agency (PVMBG) has warned that people should stay 300 meters away from the river.  Evacuation has been hindered by damage to roads and bridges, as well as by heavy traffic from people coming in to see the disaster.

An interesting side-bar mentioned in the DredgingToday.com article linked in the figure caption is that the dredging of the Code River has been hampered by the lack of heavy machinery.  However, people living near the river have been helping by manually carting material away.  Apparently it is well known that the volcanic mud is rich in nutrients, and a truck of this material is fetching 50-60 thousand Rp! (50,000 rupiahs convert to about $5.50 US.)

1 comment:

Anonymous said...

My partner аnd I absolutеlу love уоuг blog and fіnd the majority of your post'ѕ tο be
what preciѕеly I'm lοoking fοr.
Do you offеr guest wrіtеrs tο write cοntent in yоuг
cаsе? I wouldn't mind сomposing а ρost οr elaborating on most of the subjeсts уou write related to here.

Agaіn, аwesοme blοg!

Review mу web-ѕite ata ptx-4