Near real-time data collection during tephra fallout: a new monitoring system at Tungurahua volcano

Abstract:

Tephra fallout has been Tungurahua’s most frequent and widespread volcanic hazard since October 1999, directly affecting thousands of residents, disturbing air traffic, and greatly impacting the local agriculture. In order to have near real-time information on the tephra fallout we installed a new low-cost system in seven strategic locations around the volcano in December 2010 and April 2011. The system is based on three elements: 1) cylindrical containers; 2) electronic portable scales; and 3) trained volunteers. The cylindrical container is placed in an open area near the volunteer’s house and collects the tephra during the eruptive phase. The volunteer retrieves the cylindrical container once or twice per day depending on the fallout rate and weights it with the electronic portable scale. Then he or she reports the measurement to the Tungurahua Volcano Observatory via radio with some observations on the sample characteristics. Additionally, the volunteer collects the sample for further investigation. This system allowed us to acquire 159 data points and 91 samples during three eruptive periods (December 2010, April to May 2011, and November 2011 to May 2012). During these periods most of the ash plumes were driven toward the west. The Choglontus area, located 6.5 km WSW from Tungurahua’s crater, was the most affected by tephra fallouts with a total accumulation of more than 27 kg/m2 since December 2010. The peak fallout rate was registered in Runtun, located 5.8 km NNE from Tungurahua’s crater, on April 29, 2011 with a value of 2.5 kg/m2 in only 7 hours. Studies of the tephra samples provided critical information such as the shift …

Año de publicación:

2012

Keywords:

Fuente:

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