A tsunami triggered by a magnitude-8.0 quake in the South Pacific has killed at least six people on the small Santa Cruz Island.
The Pacific Tsunami Warning Center (PTWC) issued a tsunami alert for the whole Solomon archipelago and other South Pacific nations six minutes after a strong quake had been recorded at 12:12 p.m. local time (1:12 a.m. GMT) at 38.7 kilometres depth 70 kilometres west of the town of Lata on Santa Cruz Island, also known as Nendo.
The warning triggered evacuations across the region, but it came too late for some villagers on the remote island.
According to reports, a tsunami measuring 0.9 metres in height flooded several villages near Lata and the town’s small airport. The number of casualties may still rise, as the full extent of damage in the area has not yet been assessed.
“The international warning system worked well in this case,” says Tom Worthington of the Australian National University in Canberra. “However, there are limitations to the local warning which can be given, due to a limited number of tsunami sensors in the Pacific and limited communications in some countries.”
The PTWC cancelled its tsunami warning for the wider Pacific region at 3:47 a.m. GMT.
The 8.0 quake was preceded by a 6.3-magnitude shock at 11:07 a.m. local time, the US Geological Survey reports. Over the past seven days, geologists have observed a total of seven shocks of magnitude 6-plus.
The eastern margin of the Australia tectonic plate is one of the most seismically active areas of the world. On 1 April 2007, a tsunami following a magnitude-8.1 quake killed more than 50 people and destroyed numerous villages on the Solomon Islands.
But researchers are still struggling to quantify the actual quake and tsunami risk in the region. “We know very little about the long-term earthquake and tsunami activity of the entire Solomon Islands region and so cannot say with any confidence whether this type of event we have seen today is out of the ordinary or how often we might expect it to happen in the future,” says Richard Arculus, a geologist the Australian National University.