Commentary: No respite for disaster-weary Japan

Commentary: No respite for disaster-weary Japan

But there are ways to mitigate the impact of these hazards and improve Japanese society’s resilience, say two experts at the Earth Observatory of Singapore.

Police officers search for survivors from a house damaged by a landslide caused by an earthquake in
Police officers search for survivors from a house damaged by a landslide caused by an earthquake in Atsuma town, Hokkaido, northern Japan, in this photo taken by Kyodo September 7, 2018. Mandatory credit Kyodo/via REUTERS

SINGAPORE: Japan is getting no respite this year after getting hit by an unprecedented number of natural disasters — earthquakes, a typhoon, torrential rains, floods and a heatwave.

Then, without warning once more, another earthquake struck the already distressed country. 

This time, it was a 6.6-magnitude earthquake that shook the northern island of Hokkaido and left several dead or missing in its wake.

Are these separate disaster events somehow connected to one another?

READ: The Osaka earthquake brings Japan one step closer to its next major rupture, a commentary

SUSCEPTIBLE TO NATURAL HAZARDS

From a scientific point of view, there is no evidence so far that shows a clear correlation.

The change in climate alone is likely to have increased the risks of floods, typhoons and landslides after earthquakes in Japan and elsewhere in the world.

However, climate change and earthquakes are unrelated natural disasters, which is why the preparation and mitigation of these hazards are conducted in a parallel manner.

So can Japan guard itself against such phenomena?

Landslides caused by an earthquake are seen in Atsuma town
Landslides caused by an earthquake are seen in Atsuma town, Hokkaido, northern Japan, in this photo taken by Kyodo September 6, 2018. Mandatory credit Kyodo/via REUTERS

Like many other countries that sit along the western margin of the Pacific Ocean, Japan is susceptible to several forms of natural hazards – whether earthquakes, typhoons or floods.

Looking specifically at earthquake hazard mitigation, scientists have to study the country's historical earthquake records, the likely ground shaking from earthquakes, and the potential earthquake sources in the future.

From the data collected from these studies, scientists can begin to understand the spatial and temporal distributions of these earthquakes and then go on to produce seismic hazard maps of those areas.

Based on these hazard maps, along with other data like ground motion observations, earthquake engineers will review established building codes and standards in order to make buildings and infrastructures more earthquake-resistant.

A building damaged by a powerful earthquake is seen in Abira town
A building damaged by a powerful earthquake is seen in Abira town in Hokkaido, Japan, on Sep 6, 2018. (Photo: Reuters/Kyodo)

READ: Japan floods a warning of a changed climate, a commentary

GREAT VALUE IN EARLY PREPARATION

Apart from this, there is great value in education when it comes to disaster preparedness.

It is especially valuable to learn the right steps to take in the event of a catastrophe. The Drop-Cover-and-Hold is a popular earthquake survival technique that is taught to those as young as pre-schoolers, just as being aware of the right time to evacuate a building is.

For earthquake-prone countries like Japan, regular earthquake drills can also serve to improve the resilience of the society and the survival of its residents.

Other early preparation approaches are available too, but they stretch beyond the scope of science.

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Children at Toyama Nursery School in Shichigahama, Japan. The school was badly damaged in the 2011 earthquake-tsunami and was rebuilt with donations from Singapore. (Photo: Rachel Ng/SRC)

For example, government policies and funding play a critical role in hazard mitigation. Effective usage of a government's budget in hazard preparation should adequately cover scientific research. 

This includes both fundamental and applicable types of research, general education, emergency responses, information sharing, strategic planning, and even the forcible execution of land use.

Other approaches, like insurance and re-insurance, could provide some degree of additional relief from the financial pressures culminating from the destruction and damage to property.

To defend against the physical ground-shaking from powerful earthquakes, earthquake-resistance should be worked into the design of buildings and other infrastructure.

MORE RESEARCH CAN REDUCE EXPOSURE

Fundamental scientific research and survey are key factors when evaluating the potential risks of natural hazards that a country is exposed to. 

For example, extensive disaster simulations and the accurate mapping of potential flood zones prior to the design and construction of a building or infrastructure could effectively reduce the country’s (and local communities') chances of exposure to coastal flooding hazards.

Western Japan suffered devastating floods and landslides earlier this month
Western Japan suffered devastating floods and landslides in July. (Photo: AFP)

A thorough understanding of the area's sub-surface geology could also help scientists and engineers more accurately evaluate the potential risks of soil liquefactions inside a city, and thus be able to decrease the chances of allotting a high-value infrastructure to a high-risk area.

Such steps could go a long way in minimising the destruction and loss of lives that result from natural disasters of such formidable force.

Assistant Professor Wei Shengji is a principal investigator at the Earth Observatory of Singapore. Dr Wang Yu is a visiting scientist at the same observatory.

Source: CNA/sl

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