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Krakatau before 1883 (Ancient Krakatau)
The Islands of Sertung, Panjang and the base of Rakata are considered to mark the boundaries of a large submarine caldera with an approx. diammeter of nearly 8km (Deplus et al., 1995). This caldera is thought to be the result of an earlier eruption of similar magnitude to the 1883 event. Based on an excerpt from the Pustaka Raja (Javanese Book of Kings), the eruption was initially dated to 416 AD. Here it is suggested that a volcano (probably Krakatau) erupted violently and burst apart before sinking into the sea. The sea rose and inundated the land and Java and Sumatra were divided into two parts. The accuracy of this account is however disputed since there is no coroborating scientific evidence for a large eruption at this date and the link between an eruption of Krakatau and the seperation of Java and Sumatra is questionable. Nevertheless, the account of the eruption bears striking similarity to the eruption of 1883 since it appears to describe a violent ultimately caldera-forming eruption associated with tsunamis.
Tree-ring and ice-core data suggest that a major volcanic eruption with global climatic impact occurred in 535AD. Keys and Wohletz (Wohletz 2000, Los Alamos National Laboratory, LA-UR 00-4608) propose that a massive eruption of Krakatau too place at this date and argue (taking the account of the division of Java and Sumatra by the eruption literally) that the Sunda Straits are actually the resulting huge, about 50km diameter, caldera. Present-day Krakatau is located on the SW border of this proposed caldera. Whilst the correction of the dating from 416AD to 535AD is based on scientific studies, little general support is found for their massive caldera hypothesis. In fact, the Sunda Strait is generally attributed to the clockwise plate-tectonic rotation of Sumatra relative to Java (Nishimura et al., 1992. GeoJournal 28, p.87-98). Based on data obtained from the analysis of drill-holes in the sediments surrounding Krakatau, Ninkovich suggested a completely different date for the major eruption shaping the pre-1883 caldera (Ninkovich, 1979. J. Volc. Geotherm. Res. 5, p.67-86). However, his estimation that the eruption occurred 60000 years ago is not widely accepted.
Following the 416(/535)AD eruption, historical records appear to suggest eruptions around 850, 950, 1050, 1150, 1320 and 1530 although no accurate record exists of the date or type of eruption. The 1680-1681 and 1684 events were at least partially documented by dutch mariners and appeared to have centered around Perboewatan cone. Both involved explosive activity and the former involved emplacement of lava flows (Smithsonian GVP - Eruptive History Krakatau).
Krakatau before 1883 (Ancient Krakatau)
The Islands of Sertung, Panjang and the base of Rakata are considered to mark the boundaries of a large submarine caldera with an approx. diammeter of nearly 8km (Deplus et al., 1995). This caldera is thought to be the result of an earlier eruption of similar magnitude to the 1883 event. Based on an excerpt from the Pustaka Raja (Javanese Book of Kings), the eruption was initially dated to 416 AD. Here it is suggested that a volcano (probably Krakatau) erupted violently and burst apart before sinking into the sea. The sea rose and inundated the land and Java and Sumatra were divided into two parts. The accuracy of this account is however disputed since there is no coroborating scientific evidence for a large eruption at this date and the link between an eruption of Krakatau and the seperation of Java and Sumatra is questionable. Nevertheless, the account of the eruption bears striking similarity to the eruption of 1883 since it appears to describe a violent ultimately caldera-forming eruption associated with tsunamis.
Tree-ring and ice-core data suggest that a major volcanic eruption with global climatic impact occurred in 535AD. Keys and Wohletz (Wohletz 2000, Los Alamos National Laboratory, LA-UR 00-4608) propose that a massive eruption of Krakatau too place at this date and argue (taking the account of the division of Java and Sumatra by the eruption literally) that the Sunda Straits are actually the resulting huge, about 50km diameter, caldera. Present-day Krakatau is located on the SW border of this proposed caldera. Whilst the correction of the dating from 416AD to 535AD is based on scientific studies, little general support is found for their massive caldera hypothesis. In fact, the Sunda Strait is generally attributed to the clockwise plate-tectonic rotation of Sumatra relative to Java (Nishimura et al., 1992. GeoJournal 28, p.87-98). Based on data obtained from the analysis of drill-holes in the sediments surrounding Krakatau, Ninkovich suggested a completely different date for the major eruption shaping the pre-1883 caldera (Ninkovich, 1979. J. Volc. Geotherm. Res. 5, p.67-86). However, his estimation that the eruption occurred 60000 years ago is not widely accepted.
Following the 416(/535)AD eruption, historical records appear to suggest eruptions around 850, 950, 1050, 1150, 1320 and 1530 although no accurate record exists of the date or type of eruption. The 1680-1681 and 1684 events were at least partially documented by dutch mariners and appeared to have centered around Perboewatan cone. Both involved explosive activity and the former involved emplacement of lava flows (Smithsonian GVP - Eruptive History Krakatau).
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