Volume 1

Netherlands East Indies / by S.H. Beaver [and others].

  • Great Britain. Naval Intelligence Division
Date:
1944
Catalogue details

Licence: Public Domain Mark

Credit: Netherlands East Indies / by S.H. Beaver [and others]. Source: Wellcome Collection.

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    and the rapid erosion of its flanks by torrential streams has caused much fluvial deposition. To some of the localities within 15 km. (10 miles) of the crater, however, the volcano has brought much destruction. _ The ‘scorching clouds’ had been observed on several occasions, but they were first scientifically studied in 1920-21, and the 1930 eruption provided more grand but catastrophic examples. The greatest avalanche rushed down the Blongkeng ravine and spread out - over the land below, extending for 12 km. and destroying 20 sq. km. of country, including thirteen villages (with twenty-three more partly destroyed) and annihilating 1,369 people and 2,100 animals. ‘The ash clouds were so thick that the ground was covered for depths of up to 40 cm. (15 inches). This eruption left a great cleft, 850 m. long and 250 m. deep, near the top of the mountain; as a result the old lava _ plugs in the crater collapsed. The following year a new lava stream spread slowly down the side for a distance of 2 km., accompanied by scorching clouds and rains of ash. Further big eruptions of lava in 1934 spread ash as far west as Bandoeng, 320 km. (200 miles) distant, and produced a new lava flow which generated ladoes and scorching clouds. _ Merapi is carefully watched. In 1931 an electric rain-gauge was set up to give warning of excessive falls which might cause lahars; a warning given by this means in 1932 probably saved some loss of life, though it could not of course prevent the damage to ricefields and villages. In 1937 a siren was installed at one observation post to warn certain of the more vulnerable villages. Keloed (Figs. 19 and 20). Keloed rivals Merapi in destructiveness, despite its comparative insignificance amongst the Javanese volcanic giants. Its summit rises to a mere 1,731 m. (5,676 ft.), but the crater contains a lake which has several times overflowed during periods of activity. Since 1811 there have been six eruptions, each accompanied to a greater or less extent by lahars resulting from the ejection of the lake water, and by scorching clouds. The peak of Keloed is an andesite mass, possibly the lava plug of an ancient volcano. On the south-west side of the crater, Goenoeng Soembing (1,530 m.) is a lava-dome, partly destroyed so that the columnar structure of its interior is now visible. ‘The northern wall of the crater is solid lava. ‘The crater rim is broken on the south- western side; this breach is largely the result of the 1848 eruption; the col is at just over 1,200 m. (3,g00 ft.), and it is this which allows the lake to overflow down the Lahar Badak gorge (Plate 6).
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