Usually, when you think of an earthquake you’ll be expecting it to last for seconds or maybe minutes. But it can last much longer. Even years!
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@kralizec and subscribe to my Youtube channel at Kralizec Gaming Youtube ChannelEarthquakes tend to be quick. Most of the time, they last a few seconds or maybe minutes. Some clusters can last days, weeks, or even months. And very rarely – years. Usually as indistinct shakes. But new research coming from Singapore shows that sometimes earthquakes can be much longer-lasting. They discovered a natural record of a quake sequence that lasted more than three decades.
Earthquakes are usually caused by pressures that occur when tectonic plates meet. And then, at a certain point, the mass moves and quakes happen. This shift is usually sudden and quick making the earthquake short but usually quite intense. But at other times, tectonic plates move slowly. This also creates vibrations but these are usually weak but last much longer. These can only be detected with our most powerful equipment.
Geologists call them SSEs – slow slip events. Most often, these last for a few weeks but we did observe an earthquake that lasted for three years. Now, Rishav Mallick from the Earth Observatory of Singapore at the Nanyang Technological University and his colleagues recently tracked down an earthquake that may seem quite absurd.
The researchers observed micro-atolls. These strange structures are made from corals near the coast of Sumatra in Indonesia. These micro-atolls were created very slowly and are a valuable source of detailed information about changes in the sea level and the movements of minerals. The results show that from 1738 to 1829 the micro-atolls grew at a steady pace of 1 – 2 millimeters per year. But then in 1829 something changed. The speed dramatically increased to about 10 millimeters per year and lasted until 1861.
The scientists believe the most plausible explanation is that a very long-lasting and weak earthquake took place in the area. And it lasted 32 years! And it also ended quite dramatically as in 1861 a devastating earthquake took place in Sumatra reaching 8.5 on the Richter scale. Thousands died. Now, Mallick and his team are convinced that by monitoring the tiniest of earthquakes we could perhaps predict the more serious ones.
