VOLCANIC GROUP

OBJECTIVES RESEARCH

We are interested in Physical Volcanology and volcanoes activities.

PEOPLE

This Group led by Dr. Kirbani. The members are students who interested to Physical Volcanology.

RESEARCH AREAS :

	Merapi Volcano (Yogyakarta)
	Krakatau Volcano (Sunda Strait)
	Semeru Volcano (East Java)
	Slamet Volcano (Central Java)
	Ijen Volcano
	Kelut Volcano (East Java)
	Batur Volcano (Bali)
	etc.

RESEARCH RESULTS

	Maximum Risk Prediction of Merapi Volcano Eruptions (RUT)
	Cooperation with GFZ Germany on Physical Volcanology Research (Together with VSI)
	Basic Science Research on Physical Volcanology (Merapi, Krakatau, Semeru Volcanoes) (Dirjen Dikti)
	Seismicity Measurement at Mount Krakatau by Means of Broad Band Seismometers
	Non Linear Analysis of Volcanic Tremor at Mount Krakatau
	Dynamic of Chaotic Vibrations of Pendulum
	Study on Low Frequency Volcanic Tremor at Merapi by Means of Broad Band Seismometers

RESEARCH LINKAGES

	Scientific Cooperation with Juelich Research Center (KFA), University of Stuttgart, Geophysical Research Center (GFZ) Potsdam, University of Darmstadt., etc. in Germany in Physical Volcanology, especially research in the Merapi, Krakatau, Semeru Volcanoes. A telemetry seismic station network has been installed on the merapi volcano. It consist of three broad band three component seismometers.
	Research Cooperation with Directorate of Volcanology on the maximum risk evaluation of the Merapi Volcano's eruptions, in connection with the outstanding integrated research (RUT II)

RESEARCH

QUALITY FACTOR (Q) OF MEDIUM PROPAGATING

SEISMIC WAVES ON SLAMET VOLCANO

BY SPECTRAL RATIO METHOD

 By

 Awan Sulistyanto Nugroho

 ABSTRACT

              A preliminary seismic investigation on Slamet Volcano has been conducted by measuring the seismic signal from elevation of 1550 m above MSL to the summit of 3428 m above MSL on September 16^th-21^st, 1997. Each point of measurements was recorded for at least 1.5 hours and especially for measurement at the summit has been done for 6 hours continuously.

            Lennartz long period three components seismometer (Le-3D/5s) with natural frequency 0.2 Hz was used for rover station and three Kinematric one component seismometers with natural frequeny of 1 Hz were used for base station. All these seismic stations adjusted to record the signal at rhe same time.

            One to twelve Hz dominant frequency spectra could be seen from the velocity seismograms. The values of medium quality factor (Q) in Slamet Volcano based on the spectral ratio method found to be 26-138 l/dB and by assuming the velocity of the P wave on the medium is 1500 m/s, from the Q factor resulted, the absorption coefficient is (0.82-8.7).10^-4 dB/m for the frequency  of 5-11 Hz.