The Cost Incomplete Worst Case Scenario Jakarta Post 29 May 2006

The Cost Incomplete Worst Case Scenario

Jonatan Lassa*

While many evacuees had just returned their home after being evacuated for almost a month anticipating the eruption of Merapi mount, all of a sudden, an unexpected devastating earthquake shaken both Jogjakarta and Central Java, Indonesia last Saturday (27/05). Out of the blue, the reality has turned to prove that the wish for the spiritual power that would have saved people’s lives from volcano eruptions is nonsense, in the sense that fatality in mask of “local wisdom”, thus a contra to disaster preparedness. Prayers for protection from volcano eruption thus “answered” by a devastating earthquake.

The latest media report on the death toll almost reached 5,500. The media and TV are now covered by the disaster in their headline news. Tears, deaths, moaning and shocking due to the Jogjakarta earthquake replace all Merapi news. Indonesia’s Metrological and Geophysical Agency (BMG) claims that the earthquake was truly a “purely” tectonic earthquake, denying that it was indeed a combination of volcano-tectonic eruption. The question is that are BMG and mainstream scientists and experts trying to mask their failures to communicate the worst case scenario to the policy makers and the people?

Be it a tectonic earthquake, a reasonable emergency planning for volcano must include pre-eruption (volcano) earthquake. Regardless the last Saturday's earthquake was tectonic or volcano or even combination of both, people should be prepared for another following risk of volcano such as an earthquake.

Even though too early to claim either the earthquake is a combination of both volcano and tectonic one, the fact is that the BMG and scientists should know that pre-eruption earthquakes are normal in volcano activities. Experiences from Vesuvius mount of Pompeii in 79 A.D and Pinatubo mount in the Philippines in 1991 show that pre-eruption earthquakes are normal. This was something missed from the attention of scientists, BGM and disaster experts in Indonesia. Scientists and policy makers had failed to communicate another risks of volcano hazards, that apart from its magmatic eruption, earthquake risks (either volcano or tectonic) might happen.

It further shows that the importance of multi hazards approach to risk mapping and emergency planning is crucial. What has happened is that there was a collective failure to include and communicate volcano earthquakes as risks as part of the worst case scenario.

I am not going to say that building up and communicating ”worst case scenario” of volcano eruption made ex-ante is easy. However, it is true that every possible known risks should be counted/mapped and then communicated, in order policy makers to have better disaster preparedness and contingency planning.

It is a common knowledge for every one to understand that an earthquake could be of volcano, or tectonic or combination of both. Pre-eruption earthquakes must be factored in the disaster preparedness. This is also the missing points that media failed to raise up, as they, together with most practitioners sunk in the romantism of local wisdom that proved not enough in volcano mitigation.

You don’t have to be an expert as wikipedia and books at the bookstores and the internet have educated people that there is a so called volcano-tectonic earthquake to be anticipated and mitigated. An earthquake might be due to volcano activities such as stress changes at the solid rock related to both injection and/or withdraw of magma. The phenomenon is called volcanic-tectonic earthquake. This type of earthquake is expected to cause huge cracks as the rock moves to fill the empty rooms left by withdrawal magma. Even thoug this type of earthquake says nothing about the scale and time of eruption, but indeed it can happen any time.

Another type of volcanic earthquake is a rather long term one due to changes of stresses resulted from unstable transportation of magma surrounding the rock. If the injection of magma sustains, many tremors will happened and thus an indication to be cautious for the eruption.

In the context of Jogja disaster, the first was very likely to happen despite of the opposite claims from BMG and mainstream disaster experts. While no certain either with the second type of volcanic eruption nor the formal claim that the eruption was merely ‘tectonic’ in it self is very unlikely.

Garbage in garbage out: a Mislead Emergency Planning?

All should admit that there had been emergency planning in place. What was wrong is that not all risks are counted and prepared. Thus, earthquake risks were simply ignored and people were so busy with the preparation for the dealing with “Wendhus Gembel, the erupted poisonous clouds, erupted from the Merapi mount.

Incomplete pictures of risks that should be communicated by the governmental scientists and mainstream disaster experts had mislead the media not to let the people be aware of the deadly consequences brought by a volcano-tectonic earthquake.

During twelve years studying earthquake mitigation, back to first deal in 1992 Flores earthquake up to now, not a single case shows that people are killed by earthquakes but of collapsed houses and buildings. Thus the only solution ex-ante is earthquake mitigation, ranging from specific treatment for all non-engineering and engineering structures to public educations. Sadly, this vital information simple missed as the people see volcano risks by neglecting earthquake risks.

Emergency planning in place is more than enough but won’t be effective unless it is based on a complete picture of risks mapping. A very expensive lessons from Jogja for every one, especially disaster experts and scientists and policy makers for managing volcanic crisis in the future.

*.based in Banda Aceh