Of more importance than the flank eruptions are the excentric eruptions, which are fed from a much more deeper lavaniveau than the first mentioned, whereas the breakthrough mostly takes place in the area of the volcano foot. Also excentric eruptions may entirely independently become active fron the main crater, which at flankeruptions is not likely possible. Also the phenomena, with which excen…
At the end of February 1920 by the Sectionhead of the Irrigation at Lumajang was reported, that in that month an abnormal drop of the waterlevel of the Ranu's Klakah and Pakis had taken place. If the Ranu Klakah in normal times always flowed through his nator al outlet, at present it is not like this, as the lake level has drop till 1.5 m below the outlet This even happens during the full W …
As already earlier mentioned the G. Herapi exists of two morphologic clearly to be distinguished parts, an older eastern and a younger western part. From the sunnit of the old ringdike, only a small part remains (see portrait 14), of which the eastern part is named G. Pusunglondon (2694.3 a.s.) and the northern G. Paseban (2679= a.s.). The old volcano mantle of the G. Merapi has grown much more…
The spreading of the Herapi products is of a great agrogeologic Importance, as the Merapi products compared with the rocks of other Java volcanoes are extraordinary fosforrich. Only towards one side these products could develop feely, namely in the plane of Solo, whare they border to that of the Lavu. To the S the spreading was stopped by the southern mountains, only in the area of the kali Opa…
A few volcanoes of Indonesia posses such a voluminous literature lize the G. Kelut. The are less the volcanic phenomena, than the destructions caused by the mudstreams (lahar), which all times attracked attention. It in true that our through knowledge of out bursts does reach farther than until the begin of the ninetienth century, but the literature of that era is so rich of date, that we howev…
On October 12, 1920 the inhabitants of the most high laying kampungs in the vicinity of the Blongkengravine were surprised by hot dustclouds and were killed by the burns. It appeared inmediately, that there was no outburst at all, as the summit slopes of the Merapi were, as far as they were overgrown in August and September, were still green as before (the reports from news papers concerning th…
Still a single word on the built up of the volcano as appears from the exposures out side the crater. In all ravines visited by the author, this are the lahar Badak, the lahar Siwalan, the Kali Ijir and the lahar ligobo, the number of lava out flows was not to be called a few. On portrait 17 we see more of such andesite break-through exposed in the ravine of the lahar Ngobo. Remarkable is the f…
The history of the outburst of the Kelut is very monotonous. Each eruption has caused Lahans and these mudheaps always Tork retains, desa's destroyed and in the last time also planta terms.
In the night of May 19th to the 20th, 1919 the nature powers again have shown their everything destructing violence. The contents of the craterlake of the G.Kelut was suddenly ejected over the craterwalls.
In accordance with Lorie and Prof. Behrens we have determined all collected samples as real basalts. The microscopic praeparates only show difference in relative number and size of the separated crystalls between them, and with respect to the groundmass, also in his capacity of the groundmass itself. As conson with basalt, the olivine exclusively appears as porphyric separation and not in the g…