Comparison of the 2011 Japan earthquake and tsunami with the 1960 Chilean earthquake

¶ … Chilean earthquake of 1960 and the recent Japanese earthquake, the Valdivia quake that ruptured the Chilean coastline more than five decades ago is considered by many to be the most powerful earthquake in modern times. It was the largest seismic rupture ever recorded, achieving a 9.5 rating on the Richter scale. The resulting tsunami affected nearly the entire Pacific rim, causing substantial damage across Chile, Hawaii, Japan, New Zealand and Australia. The primary tsunami wave sped to Hawaii, where it devastated the town of Hilo. Waves higher than 30 feet were recorded in the Philippines and Japan in mere hours following the initial shock.

Most accounts placed the death toll at roughly 6,000, while economic losses related to the quake range from U.S.$500 to U.S.$600 million (Seismo-Watch, 2011). Nearly 40 per cent of the town of Valdivia was wiped out, leaving more than 20,000 citizens homeless. Entire cities were flooded, new wetlands were created, and electrical and water facilities were crippled in the quake's aftermath. Local rivers and pipelines were stifled with debris that included entire houses and portions of neighborhoods (Extreme Science, 2011). However, the death toll remained below that of many quakes (including the Japanese quake of 2011). This is likely due to the sparse population in the surrounding region and the propensity of civil engineers to developing municipal centers on higher elevations. Additionally, most towns consisted of wooden structures, as opposed to more deadly brick-and-mortar edifices that could potential pose more threat to life when thrown about by tidal waves.

Like the Japanese quake, the Valdivia rupture was a megathrust quake. It occurred far below the earth's surface and was caused by the subduction of one tectonic plate beneath another. Subduction quakes tend to cause the largest seismic activity due to their capacity to release more built-up stress in one powerful fissure. Among the catastrophic results were a flood that nearly destroyed the entire San Pedro River Valley and a massive volcanic eruption at Cordon Caulle (Extreme Science, 2011).

The Tohoko quake that recently occurred in Japan was slightly less powerful but caused significantly more damage, mostly due to the high concentration of population and the powerful tsunami waves that rushed ashore in the subsequent hours. The magnitude of the Tohoko quake was 8.9, among the largest ever to hit the Pacific Rim. It occurred at a depth of roughly 20 miles beneath the ocean's surface. The destructive tsunami waves that resulted measured nearly 100 feet high and destroyed several towns in spite of the warnings and evacuation measures issued by local governments. While the death toll is still being tallied, current numbers confirm more than 11,300 deaths, with 16,290 people still reported missing. In addition, more than 120,000 buildings were severely damaged or destroyed. Three major nuclear power plants suffered explosions, with the resulting radioactive emissions forcing evacuations of the surrounding communities.

The total cost of the earthquake is still being determined, but most estimates place it as the most costly natural disaster ever. The World Bank recently estimated the total costs as high as U.S.$235 billion (USGS, 2011). The Japanese government has said that the total cost could ultimately be as high as U.S.$300 billion. As mentioned, this is largely due to the dense population centers affected by the quake and the low-lying urban areas that were devastated by the resulting tsunami waves. In addition, costly damages were suffered throughout the Pacific Rim, as the tsunami quickly roared across the ocean. Ultimately, 20 countries were affected by the tsunami, a number similar to that of the Chilean quake five decades previous.