For June Merapi report will be presented special in report of meeting about June 1984 Merapi activity because all data during the month was taken directly from the field or observatory
In April and May 1984 rockfalls and glowing clouds from the active lava dome were continued to be observed traveliing a maximum distance of 1.5 KM from the summit toward Batang Valley.
Material continued to fall from the active dome producing rockfalls which traveled down the Batang valley and reached a maximum distance of ffrom the summit.
October - november 1983 rockfalls from the active dome were continued to be obeserved traveling a maximum distance of 1,5 km from the summit.
This Monthly Report marks the end of the first phase of formal cooperative studies between the Volcanological Survey of Indonesia and the U. S. Geological Survey. It therefore seems appropriate to make some summary comments and statements about this two-year, mutually-beneficial program.
August and September 1983 rockfalls from the active dome of lava were continued to be observed traveling a maximum distance of 1.4 k from the summit. Seismic activity during August - September 1983 was similar to that of the previous month. Multi-phase events recorded by the seismo graph at the Babadan field observatory were relatively proportional to those rockfalls events mentioned above.
Seismicity continued at a low level during June, and no glowing clouds were observed. The number of rockfalls from the lava dome decreased; they traveled a maximum distance of 1800 meters from the active part of the dome. No significant change was observed in the frequency of multi-phase earthquakes, which remained low. Repeated photography on June 28 and 29 showed that the flow rate and extrus…