A super-fast tsunami that ravaged an Indonesian island last year, killing thousands, was almost certainly triggered by underwater landslides, according to a detailed reconstruction of the disaster using surveillance-camera and video footage harvested from amateur posts on YouTube and other social media. The findings suggest that tsunami warning systems should be upgraded in coastal regions where there is a risk of landslide-triggered events, which can arrive much more quickly than other tsunamis, although some researchers say these events are too fast even for warning tools, and that public education is the key to saving lives. The results also highlight the power of unconventional research methods. “This is such an important example of citizen science,” says geophysicist Jennifer Haase at the Scripps Institution of Oceanography in La Jolla, California, who led the study. The Indonesian disaster occurred on 28 September, when a magnitude-7.5 earthquake struck northern Sulawesi. Shortly afterwards, a tsunami hit Palu Bay, a long, narrow and densely populated inlet. The earthquake and tsunami together killed 4,340 people. Although a tsunami warning had been issued, it predicted only a small wave of about 0.5 metres. In fact, the wave reached 2 metres in much of Palu Bay and reached 8 metres in some places. Eyewitnesses also said it arrived within minutes of the earthquake, rather than tens of minutes as predicted...
Language: en
LA - en SN - 0028-0836 UR - http://dx.doi.org/10.1038/d41586-019-01544-5 ID - ref1 ER -