Preparing for ‘The Big One’: Understanding Future Earthquake Risks
The recent earthquake in Myanmar, measuring 7.7 on the Richter scale, raised awareness on the anticipated major earthquake, known as ‘The Big One’. Historically, the largest recorded earthquake was the 1960 Valdivia Earthquake in Chile, measuring up to 9.6. Currently, seismic experts are concerned about potential earthquakes along the Cascadia Subduction Zone, which could cause extensive destruction far beyond the well-known San Andreas Fault. Other regions, including the Himalayas and the Marikina Valley in the Philippines, also face significant earthquake risks.
A recent significant earthquake measuring 7.7 on the Richter scale struck Myanmar, devastating Mandalay and impacting neighboring countries like Thailand. Casualty numbers are rising, with estimates in the hundreds, and property damage reaching into the billions. This incident has underscored the unpredictability of nature, reinforcing the importance of being prepared for such natural disasters. Furthermore, it highlights the ongoing conversation surrounding the anticipated ‘Big One’, a major earthquake expected to occur at some point.
Historically, the largest earthquake recorded was the Valdivia Earthquake in 1960 in Chile, which measured between 9.4 and 9.6 on the Richter scale. It caused extensive tsunami waves affecting regions such as Hawaii, Japan, and as far as Australia and New Zealand, with estimated fatalities ranging from 1,000 to 6,000. The 2004 Indian Ocean earthquake, which produced devastating tsunamis, was recorded at 9.2-9.3, resulting in over 200,000 deaths across several countries, marking it as one of the most catastrophic earthquakes of the 21st century.
The term ‘The Big One’ initially referred to a potentially disastrous earthquake along California’s San Andreas Fault, noted in a 1953 paper by geologists Mason Hill and Thomas Dibblee. This fault spans over a thousand kilometers and could produce earthquakes with magnitudes between 7 and 8, threatening major urban areas such as Los Angeles and San Francisco. Several films have explored this narrative, notably ‘Earthquake’ (1974) and ‘San Andreas’ (2015), depicting the anticipated destruction.
Recent geological perspectives suggest that the actual Big One may arise from the Cascadia Subduction Zone, situated to the north of the San Andreas Fault, running from Vancouver, Canada, to Northern California. Predicted magnitudes for this area range between 8 and 9.2, potentially displacing millions and devastating urban centers in the U.S., including Seattle and Salem. This scenario, while not surpassing the Valdivia earthquake’s magnitude, poses a considerable threat to densely populated regions.
Analyses concerning the Cascadia Subduction Zone project tens of thousands of casualties and extensive homelessness, with infrastructural damage hindering relief efforts post-disaster. The unpredictability of such earthquakes remains a key concern, with estimates suggesting a 37% probability of a severe earthquake occurring by 2060, as indicated by studies from Oregon State University. The last significant event in this zone occurred in the early 1700s, leading to widespread damage across North America and Japan.
While popular media often associates the term Big One with the United States, geological experts warn of significant earthquake threats in other regions as well. The Himalayas, for instance, could face catastrophic earthquakes measuring around 8.0, affecting North Indian cities such as Chandigarh and Delhi. Similarly, the Marikina Valley fault system in the Philippines presents a risk of 7.0 magnitude earthquakes, potentially resulting in over a hundred thousand casualties, emphasizing the global nature of earthquake preparedness.
In conclusion, while the recent earthquake in Myanmar serves as a stark reminder of nature’s power, concerns regarding future larger seismic events remain paramount. The anticipated ‘Big One’, expected either from California’s San Andreas fault or the Cascadia Subduction Zone, poses significant threats to urban populations. Similarly, other regions, including the Himalayas and the Philippines, may face substantial seismic risks without specific timelines. Preparedness and awareness are essential in mitigating the impacts of these natural disasters.
Original Source: indianexpress.com
