4 Possible Causes of Tsunamis in the Sunda Strait According to Volcanologist ITB
Pojok Fakta. The tsunami wave that came suddenly in several areas on the coast of the Sunda Strait has claimed hundreds of lives.
Based on temporary data compiled by BNPB post until Sunday (12/23/2018) at 16.00 WIB, there were 222 people died, 843 people were injured and 28 people were missing.
This tsunami wave raises many questions, what is the real cause. The Meteorology, Climatology and Geophysics Agency suspects that there were two possible events that triggered tsunami waves around the Sunda Strait, namely the eruption of Gunung Anak Krakatau and high waves due to weather conditions in the waters of the Sunda Strait. But even that is still under investigation by certain parties.
Meanwhile, ITB Volcanologist Dr. Mirzam Abdurachman in his written statement said that the activity of the Gunung Anak Krakatau continues to stretch lately, more than 400 small eruptions have occurred in recent months.
"A big eruption occurred at 6:00 p.m. and continued until this morning. Even the eruption was heard until Sebesi Island, which is more than 10 km northeast as reported by the patrol team," he said in a written statement on Sunday (12/23/2018).
According to him, the mountain which is located in the middle of the sea or which is on the edge of the beach such as Mount Anak Krakatau is potentially very potential to produce a volcanogenic tsunami.
"Volcanogenic tsunamis can be formed due to sudden changes in sea volume due to volcanic eruptions," he said.
It was said, there were 4 mechanisms causing a volcanogenic tsunami. First, the collapse of the water column due to volcanic eruptions in the sea, it is easy to blow up a float balloon in the pond which causes ripples around it.
Two, the formation of the caldera due to a large eruption of volcanoes in the sea suddenly caused a change in equilibrium in the volume of water. Pressing the dipper into the bath then reversing it is an analogy to the formation of volcanic caldera in the sea.
"This one and two mechanism has occurred in the Krakatoa eruption, exactly 26-27 August 1883. This type of tsunami such as a tsunami is generally preceded by a sea level drop before a high tsunami wave enters the land," he said.
Three, volcanic material that landslides can trigger changes in the volume of water around it. This type of tsunami occurred on Mount Unzen, Japan in 1972. The number of fatalities at that time reached 15,000 due to the tidal wave at the same time.
Four, he continued, pyroclastic flow or often known as wedus gembel which descends down the slope at high speed when the eruption occurs, can push the water level if the mountain is on or near the beach.
This type of tsunami happened when Mount Pelee, Martinique, erupted on May 8, 1902. At that time the pyroclastic flow of Pelle Mountain which slid and down the slopes finally reached the Gulf of Naples, pushing the sea and producing a tsunami.
"Volcanogenic tsunamis due to landslides or pyroclastic flows generally will produce smaller wave heights than the two previous causes, but can be very damaging and dangerous because they are not preceded by receding sea levels, as happened in the Sunda Strait last night," he said.
But this still needs to be done research and further exploration.
"Further research is needed to ensure the main causes of the Tsunami in the Sunda Strait," he concluded.
Based on temporary data compiled by BNPB post until Sunday (12/23/2018) at 16.00 WIB, there were 222 people died, 843 people were injured and 28 people were missing.
This tsunami wave raises many questions, what is the real cause. The Meteorology, Climatology and Geophysics Agency suspects that there were two possible events that triggered tsunami waves around the Sunda Strait, namely the eruption of Gunung Anak Krakatau and high waves due to weather conditions in the waters of the Sunda Strait. But even that is still under investigation by certain parties.
Meanwhile, ITB Volcanologist Dr. Mirzam Abdurachman in his written statement said that the activity of the Gunung Anak Krakatau continues to stretch lately, more than 400 small eruptions have occurred in recent months.
"A big eruption occurred at 6:00 p.m. and continued until this morning. Even the eruption was heard until Sebesi Island, which is more than 10 km northeast as reported by the patrol team," he said in a written statement on Sunday (12/23/2018).
According to him, the mountain which is located in the middle of the sea or which is on the edge of the beach such as Mount Anak Krakatau is potentially very potential to produce a volcanogenic tsunami.
"Volcanogenic tsunamis can be formed due to sudden changes in sea volume due to volcanic eruptions," he said.
It was said, there were 4 mechanisms causing a volcanogenic tsunami. First, the collapse of the water column due to volcanic eruptions in the sea, it is easy to blow up a float balloon in the pond which causes ripples around it.
Two, the formation of the caldera due to a large eruption of volcanoes in the sea suddenly caused a change in equilibrium in the volume of water. Pressing the dipper into the bath then reversing it is an analogy to the formation of volcanic caldera in the sea.
"This one and two mechanism has occurred in the Krakatoa eruption, exactly 26-27 August 1883. This type of tsunami such as a tsunami is generally preceded by a sea level drop before a high tsunami wave enters the land," he said.
Three, volcanic material that landslides can trigger changes in the volume of water around it. This type of tsunami occurred on Mount Unzen, Japan in 1972. The number of fatalities at that time reached 15,000 due to the tidal wave at the same time.
Four, he continued, pyroclastic flow or often known as wedus gembel which descends down the slope at high speed when the eruption occurs, can push the water level if the mountain is on or near the beach.
This type of tsunami happened when Mount Pelee, Martinique, erupted on May 8, 1902. At that time the pyroclastic flow of Pelle Mountain which slid and down the slopes finally reached the Gulf of Naples, pushing the sea and producing a tsunami.
"Volcanogenic tsunamis due to landslides or pyroclastic flows generally will produce smaller wave heights than the two previous causes, but can be very damaging and dangerous because they are not preceded by receding sea levels, as happened in the Sunda Strait last night," he said.
But this still needs to be done research and further exploration.
"Further research is needed to ensure the main causes of the Tsunami in the Sunda Strait," he concluded.
Comments
Post a Comment