Earth Observatory Blog

Submitted on 15 Jan 2020 by:

As at 5 pm on 15 January 2020, the Philippine Institute of Volcanology and Seismology (PHIVOLCS) reported that Taal volcano’s eruption is still going on and retained the Alert Level for Taal at 4 (hazardous eruption imminent), where further eruptions are likely to occur in the coming hours or days.

The volcano continues to send dark grey steam-laden volcanic plumes up to 700 metres (m) in height drifting to the southwest of the volcano, and new cracks on the ground have been reported in several locations around the volcano. New observations indicate that the Main Crater Lake and parts...

Submitted on 14 Jan 2020 by:

As at 1 pm on 14 January 2020, the Philippine Institute of Volcanology and Seismology (PHIVOLCS) retained the Alert Level for Taal volcano at 4 (hazardous eruption imminent), which means that further eruptions are likely in the coming hours or days.

The volcano continues to spew lava fountains up to 800 metres (m) in height from several craters, sending volcanic plumes to the southwest of the volcano. These lava fountains are emitted from the Main Crater and several vents on the northern flank of the volcano. In addition, new fissures or cracks were reported at several locations around the...

Submitted on 12 Jan 2020 by:

A continuous eruption from Philippines’ Taal volcano was observed on Sunday, 12 January 2020, at 5.30 pm (Singapore time). The powerful eruption sent an ash plume 10-15 kilometres (km) into the atmosphere and ashfall as far as Quezon city 65 km away, with volcanic lightning seen flickering continuously in the plume above the volcano. This prompted the Philippine Institute of Volcanology and Seismology (PHIVOLCS) to raise the alert level to Alert Level 4 (hazardous eruption imminent).

Alert Level 4 means that further eruptions are likely in the coming hours or days. The residents of Volcano Island, as well as communities within 14 km of...

Submitted on 12 Nov 2019 by:

Located high in the mountains are structures called “mountain huts” that provide refuge and safety to those who are in need of food and shelter. However, because of their location, these life-saving shelters are highly vulnerable to the projectiles from nearby erupting volcanoes.

In a study jointly conducted by scientists from the Earth Observatory of Singapore (EOS) and the University of Canterbury (UC), we looked at an eruption event in Japan to learn what we can about how to reduce the impacts of projectiles on roofs of building structures. Our findings were recently published on 7 November 2019 in the Journal of Volcanology and Geothermal Research.

We wanted to see...

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...

Submitted on 09 Jul 2019 by:

 

On 5 July 2019 at 1.33am (Singapore time), a Mw 6.4 earthquake struck the town of Ridgecrest in California. Its seismic waves could be felt from Los Angeles to San Jose. Nearly a day and a half later, on 6 July at 11.19am (Singapore time), a more powerful Mw 7.1 quake struck the same region. Because the Mw 7.1 earthquake is the largest event so far in this sequence, it is considered to be the mainshock. The events leading up to it, which include the Mw 6.4 quake, are considered to be foreshocks.

From this sequence of earthquakes, it is clear that the Mw 6.4 foreshock had triggered seismicity on conjugate faults (i.e. intersecting faults that criss-cross in a X-shape) along the Eastern California Shear Zone which runs somewhat parallel to the San Andreas Fault, but is...

Submitted on 27 Jun 2019 by:

Social media has found itself a heavyweight role in geology. By scraping Twitter and mining text data in Tweets, scientists at the Nanyang Technological University can now track where volcanic ash has fallen. This breakthrough won Assistant Professor Benoit Taisne and Professor Gao Cong the Accelerating Creativity and Excellence (ACE) Award for their research project titled “Detecting and Tracking Volcanic Ash Using Social Media Data”.

Asst. Prof Taisne, a principal investigator at the Earth Observatory of Singapore (EOS), worked closely with...

Submitted on 30 May 2019 by:

I went to Banda Aceh, Indonesia in 2006 to help assess the impact of the 2004 Indian Ocean tsunami upon the region’s rich cultural heritage. The scale of destruction caused by the tsunami was staggering. Half the city had been pulverised and all that was left was a mix of concrete, broken furniture, household items, and a colorful patchwork of shreds of clothing. We found clusters of beautifully carved stone grave markers dating back centuries amongst the rubble, half buried in mud and debris, or piled up neglected near areas being cleared by NGOs and donors for new tracts of post-disaster housing.

The same waves that killed over 150,000 people and displaced millions had reached back into the past and threatened to wipe out the historical memories of Aceh’s coastal...

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