Earth Observatory Blog

Submitted on 05 Nov 2019 by:

Today is World Tsunami Awareness Day. It is a timely opportunity to create greater global awareness about tsunamis as a geological hazard. Before asking how we can stay safe (or safer) from tsunamis, we must first think about how we might improve on the resilience of our current and future infrastructure.

Let’s start by looking at what a tsunami is. A tsunami is a series of waves caused by an underwater earthquake, a volcanic eruption, a landslide, or meteorological processes (meteo-tsunamis). 

So why is SE Asia vulnerable to tsunami hazards? First of all, SE Asia lies in a complex tectonic setting that contains many fault systems and volcanoes. Coupled with a high population density and a tight network of infrastructure in coastal areas, one can imagine just how...

Submitted on 30 Sep 2019 by:

Just after 6pm on 28 September 2018 (Singapore time), a magnitude-7.5 earthquake struck central Sulawesi. The powerful quake generated a tsunami which, along with massive landslides, devastated Palu and the town of Donggala. These resulted in more than 4,000 people dead or missing.

In an economic loss assessment report issued by Indonesia's National Disaster Management Agency (BNPB), the Palu earthquake event caused more than S$1.5 million in damages.

Today, a year later, scientists from the Earth Observatory of Singapore (EOS) and their teams are ready to share some of their findings about this earthquake-tsunami event.

A Complex Rupture Sequence

Using a combination of seismic, geodetic, geologic, and written records, Assistant Professor Wei...

Submitted on 28 Sep 2019 by:

During the early evening of 28 September 2018, a magnitude-7.5 earthquake struck along the coast of northwestern Sulawesi, Indonesia. This region hosts a famous strike-slip fault system called the Palu-Koro Fault.

Even though this is one of the fastest slipping faults in the world, it has not produced many large earthquakes during historical times. The Palu-Koro Fault was therefore thought to have a high probability of a large and destructive earthquake, and so the occurrence of the 2018 quake in Sulawesi wasn’t very surprising.

However, the landsliding that was triggered by the earthquake turned out to be unexpectedly destructive. Soon after the earthquake, witnesses described entire villages south of Palu City sinking into mud and disappearing, and it was...