Earth Observatory Blog

Submitted on 20 Jan 2022 by:

Volcanic eruptions are sometimes accompanied by clouds of ash and hot gases that travel down the slopes of volcanoes at tens of kilometres per hour. These clouds, called pyroclastic density currents (PDCs), are some of the deadliest volcanic hazards. And as we cannot easily study them in real-time, we took another approach to quantify some of the features that make them so dangerous: their speed, temperature, height, and how far they travelled.

PDCs are often controlled by gravity. They therefore usually flow from high to low elevation and follow the easiest path allowed by topography. This means that PDCs most frequently flow in channels, allowing scientists and government planners to foresee which direction they might go in the event of an eruption.

Although they travel...

Submitted on 15 Dec 2021 by:

Dear EOS Community, 

Looking back on 2021 as Director of the Earth Observatory of Singapore (EOS), I am proud of EOS’ achievements as we adapted to numerous challenges associated with COVID-19, while focusing on critical research and producing impactful studies on geohazards and climate change. 

I am indebted to the Administration Office who has worked hard to provide valuable support for research and educational efforts throughout the disruptions caused by COVID-19. Their specific responses to COVID helped to ensure health and safety in the office. All this while, they have also kept the administrative process running while adhering to changing practices of working in the office and working remotely.

Producing excellence in research

As with most of 2020, we...

Submitted on 18 Nov 2021 by:

A lot is at stake this year regarding what the climate holds for us in the future. The 26th United Nations Climate Change Conference of the Parties, more widely known as COP26, gathered world leaders to decide on climate actions that will shape our climate and its impacts on our societies. While scientists from the Earth Observatory of Singapore (EOS) could not join the physical event happening in Glasgow from 31 October to 12 November 2021, they have contributed in many other ways. Let’s find out how.

Recommendations to policymakers about how to reduce disaster risk and use nature-based climate solutions in ASEAN

EOS partnered with universities in the UK and Singapore to produce a series of reports as part of a project between the British High Commission and the COP26...
Submitted on 10 Nov 2021 by:

On 25 October 2010 at 9:42 PM local time, the people living on the southern Mentawai islands, a chain of islands located off Sumatra, Indonesia, felt a slow, gentle rocking of the rocks below their feet1. Initial reports of the earthquake indicated that a magnitude-7 to -7.2 earthquake had occurred seaward of the islands2. Five to 10 minutes later, a large wave inundated the western coasts of the islands, locally flooding areas more than 10 metres above the ground surface1. Together, the earthquake and tsunami killed more than 400 people and left 300 missing.

Such a large tsunami would typically require an earthquake of magnitude greater than 8. In this case, while the early data from the Mentawai earthquake suggested a much smaller event, a more complete assessment of...

Submitted on 18 Oct 2021 by:

Lying at the junction of several tectonic plates, Myanmar is exposed to geohazards such as earthquakes, tsunamis, and volcanic eruptions. To help prepare for these hazards, scientists produce hazard assessments using their understanding of the region’s geology and tectonic activity. They seek to answer questions such as: how do the tectonic plates interact with each other, how deep the magma is, where the faults are, and what kinds of earthquakes can we expect? 

Scientists from the Earth Observatory of Singapore (EOS) and their collaborators proposed a new 3D velocity model for the subsurface structure of the Earth’s crust and lithosphere down to a depth of 80 kilometres (km) below Myanmar. 

In this study, published in ...

Submitted on 19 Aug 2021 by:

Bangladesh, a densely populated country of over 160 million people, regularly faces climate hazards caused by flooding and typhoons. However, another natural hazard lies silently beneath the country: active tectonic faults. The fault system below Bangladesh is estimated to be able to generate an earthquake of magnitude 8.5 or greater – a phenomenally dangerous possibility, given that it lies only a few kilometres below the surface. Such an earthquake would also trigger secondary hazards: liquefaction, flooding, and possibly even abrupt shifts in the course of rivers. Despite its extreme hazard, this fault system remains poorly understood.

Bangladesh sits on the eastern border of the collision zone between India and Eurasia, where the Indian plate is subducting eastward...

Submitted on 13 Jul 2021 by:

In a world largely driven by technology, the Global Positioning System (GPS) is ubiquitous. Best known for providing positioning, navigation, and timing services, the incorporation of this system into smartphones and smartwatches has made it almost indispensable for many.

Scientists at the Earth Observatory of Singapore (EOS) have explored the use of this system for climate research by observing the amount of water vapour in the atmosphere. Atmospheric water vapour, albeit invisible, plays a crucial role in shaping the Earth’s weather and climate.

GPS radio signals travel from GPS satellites at an altitude of ~20,000 kilometres to ground receivers through the Earth’s atmosphere. Because of its physical properties, the atmosphere slows and bends the GPS signals. As...

Submitted on 18 Jun 2021 by:

Coastal communities face several hazards including tsunamis triggered by offshore earthquakes and volcano eruptions as well as storm surges generated during tropical storms.

Deposits left behind by these events provide important clues for the reconstruction of past events, enabling scientists to correctly forecast the risk posed by tsunamis and storms. This knowledge is of paramount importance for the estimated 600 million people living in coastal areas below 10 metres (m) above sea level.

One long-standing challenge has been to differentiate between sediments laid down by these storms and tsunamis. For more than 30 years, scientists were unable to distinguish between the deposits using regular methods such as sediment analysis and micropalaeontology.

But...

Submitted on 15 Jun 2021 by:

In April 1991, the authorities in the Philippines began evacuating people from their homes located within 30 kilometres (km) of Mount Pinatubo. More than 60,000 people were evacuated by early June 1991. This huge undertaking came after recommendations from the Philippine Institute of Volcanology and Seismology (PHIVOLCS), and the US Geological Survey (USGS). 

Pinatubo had not recorded any eruption in the past 500 years, yet just a few days after the evacuations, the first explosive eruptions of the volcano in centuries took place.

On 12 June gas-charged magma reached the surface of Pinatubo, creating a series of explosions that formed spectacular...

Submitted on 08 Jun 2021 by:

Did you know that the coral reefs of Southeast Asia account for a third of the world total? Spanning an area of 100,000 km2, these reefs are rich in biodiversity and provide critical services to coastal communities, including fisheries, tourism, and coastal protection. 

While reef health and resilience are often measured by metrics such as the amount of coral on a reef or the number of different species, the quality of the coral skeleton itself is also a critical part of the services reefs provide. In Singapore, we found that some coral skeletons deformed and fractured more easily than their counterparts from other reefs, which may make them more vulnerable to climate change.

As corals grow, they deposit calcium carbonate crystals underneath their tissue, building...

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