Taxonomy term

sumatra

19th-century discovery now reveals modern human arrival in Sumatra

Modern humans began journeying out of Africa by at least 75,000 years ago, eventually expanding across the planet. Evidence of these early human travels, including fossils and artifacts, is typically spotty and difficult to find. But one such discovery more than a century ago has shed new light on the appearance of humans in Southeast Asia.

19 Dec 2017

Dehydrated sediment layer made Sumatra quake stronger

Subduction zones are notorious for unleashing great earthquakes and tsunamis, such as the 2004 magnitude-9.1 Sumatra quake that caused shaking and inundations that killed more than 250,000 people and left millions more homeless. However, despite the dangerous reputations of subduction zones, their hazards are still often underestimated. New research reveals how sediments in the Sumatra Trench may have contributed to producing an even bigger earthquake and tsunami than hazard forecasts had estimated.

07 Sep 2017

Downgoing plate topography stopped 2005 Sumatra rupture

In late March 2005, a magnitude-8.7 earthquake struck off the northwest coast of Sumatra, Indonesia, rupturing a portion of the Sunda Megathrust Fault and further terrorizing a region still reeling from the devastating 2004 Boxing Day earthquake and tsunami just three months prior. The March quake, however, could have been far larger than it was, according to new research. Scientists have identified a topographic barrier on the oceanic Indo-Australian Plate — which descends under the Sunda Plate in the Sumatra Subduction Zone — that may have stopped the 2005 rupture from propagating farther.

04 Apr 2016

Sumatran strike-slip earthquakes challenge seismologists

Events may shed light on regional tectonics, alter stress on nearby megathrust

After the magnitude-8.6 earthquake and magnitude-8.2 aftershock that struck off the coast of Sumatra, Indonesia on April 11, scientists quickly identified why no tsunami followed either one: The earthquakes had occurred on strike-slip faults more than 400 kilometers offshore rather than on the Sunda megathrust fault that has been responsible for a series of large earthquakes since 2004. For all that can be explained, however, the earthquakes took most scientists by surprise. The combination of their size — they're the largest strike-slip earthquake ever recorded by most accounts — and their location is challenging the paradigm of strike-slip earthquakes and is raising new questions about the region’s tectonics.

11 May 2012

Earthquake rocks Sumatra

Updated on Oct. 1:

A second, magnitude-6.6 earthquake struck southern Sumatra, Indonesia, today at about 8:52 a.m. local time; this time, the epicenter was 215 kilometers southeast of Padang, West Sumatra. The death toll from both events has risen to at least 531 people.

30 Sep 2009