- 1680 – 1681 == May 1680 to May 1681, eruption of ash accompanied leleran lava.
- 1883 == 20 May 1883 Activity begins from Mount of Action, eruption of ash and steam blast reaches 11 km high and sound boom is heard as far as 200 km. In June volcanic activity also occurred in Gunung Danan. Paroxysms eruption occurred on 26 – 28 August. After 13:00, August 26 some eruptions occurred and reached its peak on Sunday 27 August, 10:02 pm and at 10:52 the boom was heard in Singapore and Australia. This eruption spewed the pumice and the ash reached 70-80 km high, the sediments occupy an area of 827,000 km2. This volcanic collapse caused a tsunami with an average wave height of 20 m swept away the shores of the Sunda Strait and northwest Java, causing 36,417 souls. September and October phreatic eruptions.
- 1884-1898 == February, the phreatic eruption was a continuation of October 1883.
- 1927 == 29 December, new volcanic activity takes place at the center of the caldera, northeast of the caldera base at a depth of 188 m and expressed as the birth of G. Anak Krakatau. This new crater is one line with the craters of Danan and the previous deeds.
- 1928-1934 == there was a small eruption, then in 1934 one of the erups reached a height of 6800 m.
- 1935-1940 == The eruption of ash and phreatic eruptions in the crater lake, the size of the crater lake reaches 275 X 250 m2, then in June 1940 the eruption height reached 1000-4000 m.
- 1941-1950 == Eruption in the crater lake …
- 1952 == formed new cone with center crater lake 440 m …
- 1953 == 20-23 September, the conical height reaches 116 m.
- 1959-1988 == Eruption of ashes over the years and ends with a lava jumble to the west …
- 1992-2000 == The ash eruption occurred on 8 November, the activity started with an increase in volcanic seismicity since August. Continuous eruptive activities until 2000 every day or every few minutes, spraying ash with an average height of 400-800 m and a lava jug. Lava linings occurred in November-December 1992, February 1993, April-May 1993, June 1993, January 1996, June 1996 and July 1996. The lava strands generally reached the sea, thus increasing the island’s mainland. The calculation of the material sprayed during it is lava and loose material is 22 million m3 and the addition of land 380.000 m2. Mount Anak Krakatau high reaches 305 m dml.
- 2001 == Strombolian ash eruption on July 5 …
- 2005 == On 24 – 26 September 2005, an increasing number of seismicities …
- 2007 == On 20 – 22 October 2007 its seismic activity increased again. On October 23, 2007 an ash eruption was as high as 200m. Visual observation results on October 25, 2007 (Patria et al, 2007), there is a new eruption hole in the southern wall of Mount Anak Krakatau ….
- 2008 == On 1 – 20 April an increase in activity. The results of direct observation to Mount Anak Krakatau 15-16 April 2008 showed that an ash eruption accompanied by bursting of incandescent material, takes place every 5 – 15 minutes interval with an altitude ranging from 100 to 500 meters …
- 2010 -…? == Starting October 10, 2010, an ash eruption accompanied by bursts of incandescent material with smoke heights ranging from 100 1700 m and takes place every day to date.
|The appearance of Krakatau volcanic complex geomorphology comprises the caldera wall, the formation of a volcanic cone, lava flows, terrain and coastal areas. Caldera morphology is characterized by a very steep wall formed in the northern part of Rakata Island with a sunken shape facing north. The morphology of the caldera wall on Sertung and Panjang is formed by a pre-historical paroxysmal eruption, whereas the caldera wall of Rakata formed at the time of caldera formation 1883.
The morphological appearance of these islands is characterized by the topography of the slopes that can be found in the south of Rakata Island, west of Sertung Island and east of Pulau Panjang. The morphology of this slope consists of the reinforcement of valleys and ridges and on the island of Rakata reveals a radial pattern while in Pulau Panjang and Pulau Sertung semi-radial. This morphological section is composed by the erupted pyroclastic flow deposits of 1883.
Volcanic cone morphology is found on the island of Rakata and Anak Krakatau. Rakata volcanic cone is observed clearly from a height of 500 m to the top, 813 m above sea level. The top part of Rakata is composed by volcanic plugs and pyroclastic flow deposits. Volcanic cone of Anak Krakatau consists of an old volcanic cone and a young active volcanic cone. Old volcanic cones show no real cones because the top of the cone disappears by eruption and leaves the crater wall large and the highest peak is 155.66 m dml.
The crater wall opens to the southeast, but in 1999 the old volcanic cones and active cones converge to form a large volcanic cone composed by layers of pyroclastic flows and lava flows. Prior to that, the active cone was formed in the center of the old conical crater and its highest peak in 1983 was 201.446 m. Due to periodic eruptions, the growth of the young cone becomes larger and conceals the old cone. In 2000, this young cone reached a height of 300 m above sea level.
Lava flows have a special morphology that is formed almost in all directions, consisting of several streams of volcanic activity in 1963, 1972, 1973, 1975, 1979, 1980 (Bronto, 1982), 1988, 1992, 1993 and 1996 (Sutawidjaja, 1997). This morphology shows various forms of rough surfaces that reflect lava chunks or “aa” lava, are scattered in various sizes and generally exhibit clear flow patterns and form a ridge that extends from its source toward the shore. Many of the lava flows enter the sea and add to the island.
The morphology of the plains occupies the northeastern part of Sertung Island and its surface in some places not more than 5 m high, composed of loose volcanic material and sand. The western and northeastern edges of this area often change, because this area is easily hit by large waves that cause abrasion, especially in the west wind season.