|The history of the eruption of Crater Lake Tiwu Nua Muri Kooh Fai (green lake) can be summarized as follows:
Pre 1928; A great eruption of about 200 years was calculated based on population information, about eight generations before the 1928 eruption. The eruption appeared in the form of five craters and a dome lava. Period of Rokatenda, with a center line ranging from 200 – 700 m.
1928; Eruptions occurred on August 4 – September 25, resulting in changes in the lava dome, showing eruptions in the form of four craters. Eruptions caused land damage, human casualties as many as 266 people, mostly due to the tidal waves of the sea.
1929-1963; For approximately 34 years there have been no activities that have erupted or erupted. Volcanic activity is only for fumarola activities. Finally in 1963, before January 1, 1964 a local earthquake vibrated, a roar was heard under the Rokatenda mountain, which was followed by a thick puff of smoke soaring above Mt. Rokatenda, then a lava dome emerged from the point of the 1928 eruption, accompanied by a mixture of incandescent and cold lava . The lava dome formation activity lasted a long time, resulting in the deaths of 1 person and 3 people injured. At the end of June, the height of the lava dome was approximately 51 m from the base of the dome (crater of the eruption of 1928). 2 cm thick ash along 2 km from the peak and 5 cm around the peak.
1966; An increase in activities.
1972; There was an eruption from a side crater, the former eruption of 1928, northeast of the main crater.
1973; Ash eruptions occurred on October 27 and 28. Ash rains spread across the island, with a distance of 5000 m from the point of the eruption. The thickness of the ash is about 3 cm.
1981; There was an increase in activities, on January 18 a new lava dome appeared between Mount Ili Manunai and Rokatenda.
1984; Increased activity felt by residents on May 9 and 21, also on June 3 and 7.
1985; On March 23, 1985, at 17:40 local time there was an eruption for 45 minutes, which was preceded by a small roar followed by an eruption, gusts of ash as high as approximately 1000-2000 m, with explosions ranging from 200-300 m above the peak. The location of the eruption came from the slopes of the 1981 lava dome, northwest with a size of 40 x 30 m eruption, inside from the crater lip approximately 20 m. Ash eruptions spread westward and covered the villages of Nitung, Waikoro and Koa. The average ash thickness is 3 mm. The activity shows the growth of lava domes
2008; October, an increase in seismicity
2009; April, there is an increase in seismicity…
|Rokatenda Mountain is an active volcanic island. The geology of the Rokatenda volcano was mapped by Igan Supriatman S., et al. In 2000, the results of the mapping separated the young and old Rokatenda products. Old Rokatenda is formed by lava rock and pyroclastic flow, which spread widely to the western and southern slopes of the mountain, and also consists of small cone remains at the foot of the western, southwest and southeastern Rokatenda mountains. Rokatenda (young) produces lava and pyroclastic flows, also forms small dunes including Matomere, Rokatenda and Ili Manunai…