A tsunami warning has been issued after the US Geological Survey reported a 6.1-magnitude earthquake off the coast of East Timor on May 27. The earthquake "may be capable of triggering a tsunami affecting the Indian Ocean region," according to a tsunami advisory group. According to the USGS, the earthquake occurred at a depth of 51.4 kilometres (32 miles) off the eastern edge of Timor Island, which is divided between East Timor and Indonesia.
A 6.2-magnitude earthquake shook Indonesia's North Sumatra in February, killing a dozen people. A 9.1-magnitude earthquake struck Sumatra's shore in 2004, triggering a tsunami that killed 220,000 people across the region, including around 170,000 in Indonesia.
When a tsunami with the potential to cause widespread inundation is imminent, expected, or occurring, a tsunami warning is issued. The public is warned that dangerous coastal flooding with strong currents is possible, and that it could last for several hours after first arriving.
Warnings inform emergency management personnel that the entire tsunami threat zone has to be evacuated. Local officials may need to take appropriate measures, such as evacuating low-lying coastal regions and moving ships to deeper waters when it is safe to do so. Warnings may be revised, regionally altered, degraded, or cancelled. Initial warnings are usually based only on seismic data in order to deliver the earliest feasible alert.