Earthquakes rock our planet on a regular basis. But as with many things, the danger is not distributed evenly – and when you take into account a nation’s ability to confront the aftermath of such a disaster, we discover things are not distributed evenly at all.
On any given day, it is estimated that 283 million people are exposed to the possibility of a major shakeup. Living on a fault line puts humans at risk of suffering damage or death at the hands of an earthquake.
However, many of the world's biggest cities are built on fault lines. Here are the major cities on Earth where an unexpected tremor shouldn't be so unexpected.
When accounting for overall exposure to the five major natural catastrophes (river floods, earthquakes, wind storms, storm surges and tsunamis) Tokyo remains first. But earthquakes are Tokyo’s main worry.
The capital of Japan sits spot-on the Pacific Ring of Fire, where its 37 million citizens are threatened by earthquakes and other natural disasters on a daily basis. The Ring of Fire is a tectonic plate in the Pacific Basin that is responsible for 90% of the world’s earthquakes and 81% of the world’s strongest quakes. On top of its prolific tectonic activity, Japan is also home to 452 volcanoes, making it the most disruptive geographic location in terms of natural catastrophes.
According to international organization Swiss Re, 29.4 million Tokyo residents would be exposed in a strong quake. But earthquakes are not the only natural catastrophe to factor in: monsoons, tsunamis, and floods are all prevalent in the region.
An important aspect in understanding the threat posed to Tokyo is how these events would reverberate on the world scale. That is to say, the value of working days lost from a natural catastrophe in Tokyo would affect the international economy to a greater degree than in any of the other catastrophe-prone cities, since Tokyo is a major global financial center.
Jakarta, the capital of Indonesia, sits in an area that is extremely earthquake prone. Sitting on the Pacific Ring of Fire, it is the world's second-most earthquake prone area. But the complications do not end there: a little less than half of the city is below sea level, putting it on soft soil that has the unenvious potential to liquefy if an earthquake of sufficient magnitude were to strike.
In the event of a major earthquake, an estimated 17.7 million lives would be at risk. Its elevation also places Jakarta at risk for severe flooding. When accounting for exposure to all five major natural catastrophes, it places fifth on the world scale. The 2004 Indian Ocean Earthquake (and ensuing tsunami) killed over 283 000 people. Of course, due to the nature of the region, many earthquakes of much smaller magnitude occur much more frequently – more than once a month.
Capital of the Philippines and second in line after Tokyo for world’s riskiest city overall (typhoons, volcanoes and tsunamis abound), earthquakes in this region regularly hit above 6.0 on the Richter scale.
The danger posed by earthquakes to Manila is threefold. It is, of course, snug with the Pacific Ring of Fire, making it especially susceptible not only to quakes, but also volcanic eruptions. With a population of 1.65 million citizens condensed into 15.4 square km, the danger of a close-hitting quake is enormous. And, considering the city’s current infrastructure and surrounding area, it is estimated that 16.8 million people will be exposed to injury, death or damage the next time an earthquake above a 6.0 magnitude strikes directly on the city.
The threat to Manila is worsened due to its soft soil, which presents the risk of ground liquefaction. But a disaster would not end in death and destruction: due to Manila’s importance to the Philippines economy, devastation of the city would mean economic ruin—it is projected that a sizeable quake would shake over a third of the country’s economy.
Los Angeles & San Francisco, United States of America
Due to its position on San Andreas fault line, California is the most earthquake-prone area of the United States. In fact, according to a recent World Geological Survey, California is more than 99% likely to be hit by a big earthquake – one that ranks above a 6.7 magnitude – within the next 30 years. Although both cities are highly developed, neither are fully outfitted to face a quake without shaking.
Los Angeles and San Francisco do not rate quite so high in terms of loss of production to their national economy as some of the other earthquake-prone major cities on this list (other major U.S. cities could compensate for the lost value of working days); however, the absolute effect of this loss on the world economy would be enormous. LA and SF rank 6th and 8th, respectively, on the scale indicating value of working days lost from a major disaster
Californians have long awaited the San Andreas Fault Line’s next victim—and the question has usually been, LA or San Fransisco? But scientists estimate that the Cascadia Subduction Zone, opposite the Pacific Ring of Fire and near San Fransisco, Vancouver and Portland, has the potential of unleashing a much greater earthquake than the San Andreas - an earthquake that could reach up to 9.0 on the Richter Scale, a ranking that only occurs once every few centuries.
Osaka is Japan's industrial centre, and the area of Japan most prone to earthquakes.
Osaka, Japan, ranks fifth on our list of most-exposed communities. Ranking close behind LA at 14.6 million people potentially affected by a large earthquake, Osaka, like its national counterpart, Tokyo, also sits on the Pacific Ring of Fire and is also subject to the four other major natural disasters, the one piling onto the other, increasing the risk to human life exponentially.
In fact, on a list of aggregated dangers, Osaka ranks fourth after Tokyo, Manila and the Pearl River Delta (whose main threat lies in storms and flooding, not earthquakes). The effect of a loss of productivity in Osaka would be catastrophic not only to the Japanese economy, but also the world economy, as a natural disaster in the area gives it a ranking of fourth on global impact after Tokyo, LA, and San Francisco. The threat to Osaka also lurks in tsunamis and storm surges – catastrophes with a tendency to amplify one another.