Share this story!            

Coastal belt of Pakistan needs topographical survey to avert a tsunami disaster

By Amar Guriro

KARACHI: The absence of topographical models for the cities lying in the coastal belt of Sindh and Balochistan and the sea can result in heavy losses, oceanographic experts and seismologists have warned.

The provinces of Sindh and Balochistan run a high risk for a possible tsunami due to the presence of the Makran Subduction Zone (MSZ) lying in the Balochistan region that has already been a victim of a destructive tsunami in the last century.

Experts claim that for disaster mitigation, it is necessary to conduct a bathymetrical and topographical survey of the Arabian Sea and coastal cities and towns of Sindh and Balochistan both.

Ulrich Wolf, programme specialist of the Tsunami Unit of Intergovernmental Oceanographic Commission, a department of UNESCO said, “Bathymetrical and topographical surveys are necessary to know the water levels at different positions and to understand the ocean physics to know what is lying in the sea bed. I would also suggest for a GIS survey of the coastal cities and towns along the Arabian Sea, so the authorities can identify the low lying areas that will be inundated in case of a tsunami and are better prepared for an emergency.”

Talking to this scribe, Wolf said that it is possible to identify a tropical cyclone two days ahead giving time to evacuate, however it is different in case of a tsunami as it can only be known after it is generated giving very little time for preventive measures. “Suppose in a big city like Karachi with an estimated one million inhabitants, the evacuation process would take several days, therefore an effective vulnerability reduction system is necessary.”

History reveals that MSZ has generated many tsunamigenic earthquakes in the northern Arabian Sea making the region vulnerable to tsunamis. Archival records of Pakistan Meteorological Department (PMD) show that 4,000 people were killed by the combined affects of an earthquake and tsunami off Makran coast on Nov 28, 1945, with the tsunami responsible for most deaths. Further records reveal that most tectonic activity takes place along the boundaries of the Indian tectonic plate and the Iranian and Afghan micro-plates. At least 28 earthquakes with magnitudes close to 7.0 or above are known to have occurred in this region since 1668, making the region extremely vulnerable to tsunamis as well as tidal waves.

Nevertheless, the Pakistan government has neither installed tide gauges on the coastal belt nor conducted any topographical or bathymetrical surveys of the Arabian Sea.

Massahiro Yamamoto former director general of Japan Tsunami Early Warning Centre and UNESCO adviser said that after the destructive tsunami at Sumatra Island in Sri Lanka, a network of different countries including Sri Lanka, Pakistan, India, Oman, Iran and several other countries was formed to exchange the early warning communication system.

“UNESCO has established early warning tsunami centres in countries located in the North-east Atlantic Ocean, Indian Ocean and Pacific Ocean. We are also training authorities and stakeholders to improve the communication methods for timely delivery of warnings to all the concerned,” he said.

Ardito M Kodijat, programme officer for the Jakarta Tsunami Early Warning Centre and Liaison Officer for Disaster Risk Management said, “We do not know when, where and how destructive the tsunami would be but we know the presence of the MSZ makes it necessary to prepare to reduce the level of losses.”

He said that it is also not possible to determine if the tsunami would not hit the costal belt but remain within the sea, therefore government must make preparations including construction of earthquake resistant buildings.

Tony Elliott, the head of ICG/IOTWS Secretariat of Intergovernmental Oceanographic Commission, UNESCO said that a topographical survey is necessary for the understanding of sea as well as urban planning patterns.

“Public awareness is vital for emergency evacuations and the government must introduce a system for rapid communication in case of a tsunami using existing means such as temples, mosques, churches and also radio communication, so that people may take timely actions,” he said.

Home | Karachi

Share this story!