Unformatted text preview: most show lack of
layer and poor sorting characteristic of ? Pyroclastic flows Rare facies show better sorting and cross bedding characteristic of ? Pyroclastic surges Paleomagnetic studies show the submarine pumice has oriented remnant magnetism, requiring emplacement at temperatures above
500˚C. Mandeville et al (1994) concluded that the basal parts of pyroclastic
flows entered the sea with sufficient coeherence to produce the
tsunamis. Nomanbhoy and Satake (1995) concluded all 3 possibilities could
displace enough water to produce the tsnumais, but the explosion
best fits wave forms and wave heights. Subsequent Research Carey et al. (1995) concluded that “The distal deposits…[were] derived from the upper part of gravitationally segregated
pyroclastic flows. Energetic flows spread out away from the
volcano at speeds in excess of 100 km/h and traveled up to
80 km from source. At the distal edge of this area the flows
were relatively dilute and turbulent, yet carried enough
material to deposit several tens of centimeters of tephra.
The great mobility of the Krakatau flows from the 10 a.m.
activity may be the r...
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- Fall '06
- Volcanology, Volcano, eruption, Pyroclastic flow, pyroclastic flows, pyroclastic surge