A new study of a 1,000-year-old tsunami in the Indian Ocean has found that the event was much larger than previously thought, and that it could have been caused by a different type of earthquake than previously believed.
The study, which was published in the journal Nature Geoscience, analyzed sediment cores from the Maldives and Sri Lanka to determine the size and timing of the tsunami. The researchers found that the tsunami was at least 10 meters (33 feet) high in the Maldives and more than 20 meters (66 feet) high in Sri Lanka. This is much larger than the previously estimated height of 5 meters (16 feet) for the tsunami.
The researchers also found that the tsunami was likely caused by a combination of two types of earthquakes: a shallow earthquake that occurred near the coast, and a deeper earthquake that occurred further out to sea. This type of earthquake combination has never been seen before in the Indian Ocean, and it could mean that the region is at greater risk of tsunamis than previously thought.
"The fact that we found evidence for a 1,000-year-old tsunami that was much larger than previously thought is a wake-up call," said study lead author Dr. James Goff. "We need to be better prepared for tsunamis in the Indian Ocean, and we need to understand the different types of earthquakes that can cause them."
The study's findings have implications for tsunami preparedness in the Indian Ocean region. Currently, tsunami warning systems are based on the assumption that tsunamis are caused by shallow earthquakes near the coast. However, the new study shows that tsunamis can also be caused by deeper earthquakes further out to sea. This means that tsunami warning systems need to be updated to take account of this possibility.
The study also highlights the importance of paleoseismology, the study of past earthquakes, in understanding the risk of future earthquakes and tsunamis. By studying the geological record, paleoseismologists can identify past earthquakes and tsunamis that have occurred in a region, and they can use this information to estimate the likelihood of future events. This information can help decision-makers to develop earthquake and tsunami preparedness plans that will help to protect lives and property.
