Tsunami Generation Due to Submarine Volcanic Eruptions With Phreatomagmatic Explosion or Caldera Subsidence

Abstract

An index of submarine volcanic explosivity concerning tsunami generation has been proposed on the basis of the relationship between phreatomagmatic explosion and resultant initial waveform of tsunamis. In the generation process of tsunamis due to phreatomagmatic explosion, the seawater touches magma of high temperature, after which the water evaporates in an instant with explosive increase of volume. We assume the value of this index specifically to simulate tsunamis caused by submarine volcanic eruption in Kagoshima Bay, where submarine explosion has been observed. Furthermore, tsunamis due to subsidence of a caldera near a volcanic mountain in the same bay are numerically simulated using an initial tsunami profile assumed without discussion about the emission process of magma out of a chamber through submarine volcanic eruption.

The Rare Volcano creating a Mega Tsunami out of the Wrath of Ruaumoko @

“…Taking the lower temperatures of magma as, say 600℃, the situation becomes dangerous when magma flows into sea water and gets mixed with it. A research paper Titled, "Tsunami Generation due to Submarine Volcanic Eruptions with Phreatomagmatic Explosion or Caldera Subsidence" by Taro Kakinuma, et.al [16] have dealt with the situation of magma getting mixed with water and finally leading to generation of tsunami. Before I take it up, I would like to show the photograph ( Fig.16) of lava flowing into the sea on the southeastern edge of the island of Hawaii.…”

“…The mixture produces a noxious haze when it hits the seawater made out of hydrochloric acid, steam, and shards of volcanic glass, the gas is hazardous to anyone who breathes it. We now come to Tar Kakinuma"s paper [16] Submarine explosive eruption causes not only a blow out of volcanic products but also phreatomagmatic explosions resulting in the generation of tsunamis. The author has used simple gas laws of Thermal Physics such as the Charle"s Law and has mathematically obtained the index of submarine volcanic explosivity regarding tsunami generation.…”