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Thousands of people have been evacuated on the Indonesian island of Bali and on Ambae island in Vanuatu as two volcanoes threaten to erupt.  The entire population of Ambae, around 11,000 people, is being moved from the path of the “increasingly active” Manaro volcano while more than 144,000 people from Bali have been taken to shelters as authorities warn that Mount Agung could erupt at any time.  The National Disaster Management Agency has said that 447 temporary shelters have been set up outside the exclusion zone around the volcano.  Thousands of evacuees sleep on floors and wait for something to happen.

Seismic activity continues in the volcano and the alert level for an eruption is at the highest on the scale.  A statement from Vanuatu Meteorology and Geohazards Department said “Ambae volcano is in an ongoing moderate eruption state, people in local villages could experience the danger of flying rocks, volcanic gases and acid rain.”

Experts explain that there are very good indications that an eruption is imminent.  Seismic tremors beneath the volcano are increasing in number, intensity, and the reduction in their depth in the last week is a very good indication that magma is moving up to the surface.  Another signs of an eminent eruption include gas emissions from the summit as a sign that pressure underground has become to great and bulging on the volcano’s surface.

On September 25, the area experienced 844 volcanic earthquakes and by mid-afternoon on September 26, had experienced another 300-400 earthquakes.  Seismologists say the force and frequency are alarming and it has taken much less for similar volcanoes to erupt.

Mount Agung last erupted in 1963 when more than 1,700 people were killed and hundreds more were injured.  Lava flowed for 4.7 miles from the crater for over 20 days ash reached the capital, Jakarta, about 620 miles away.  The most devastating effect of an eruption is the pyroclastic flows which are waves of superheated gas, ash and rock that can travel hundreds of miles an hour.

In the 1963 eruption, these flows devastated numerous villages, killing an estimated 1,300 people. Cold lahars caused by heavy rainfall after the eruption killed an additional 200.  A second eruption months later, led to pyroclastic flows that killed another 200 people. Minor eruptions and flows followed for almost a year.  During the 1963 eruption, there was no evacuation plan and people had seconds to minutes to escape the pyroclastic flows which led to a devastating death toll.

The National Disaster Mitigation Agency said no one should be within 6 miles of the crater and within 7.5 miles to the north, northeast, southeast and south-southwest where lava flows, lahars (a type of mudflow) or rapidly-moving white-hot ash clouds from where an eruption could reach.

Indonesia, the country of thousands of islands is prone to seismic upheaval because of its location on the Pacific “Ring of Fire,” an arc of volcanoes and fault lines encircling the Pacific Basin.  Mount Agung is 1 of more than 120 active volcanoes in Indonesia.

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