Nepal earthquake lowered Everest by up to 2.5 cm

Further analysis of the newly processed sentinel-1 satellite radar data shows that the area around the Kathmandu region was uplifted in the earthquake, while the area to the north of Kathmandu sunk (subsided).

The red region in the image below shows uplift while the faint blues to the north indicate subsidence. Mount Everest is located to the northeast of Kathamndu.

Processed Sentinel 1 results of the Nepal earthquake deformation. red = mostly subsidence, blue = mostly uplift.  Source: Pablo Gonzalez – LiCS/COMET+

Processed Sentinel-1 results of the Nepal earthquake deformation. red = mostly uplift, blue = mostly subsidence.
Source: Pablo GonzalezLiCS/COMET+


The image was produced by COMET researchers at the University of Leeds as part of the Look Inside the Continents from Space (LiCS) project led by CGS scientist Professor Tim Wright.

New computer modelling results estimate that the amount of lowering experienced in the Everest region could be up to 2.5cm. These numbers are very preliminary and will be verified over the coming days with further research.

8 million in need of humanitarian aid in Nepal

8 million people in need of humanitarian assistance in Nepal after a powerful magnitude 7.8 earthquake shook the country on April 25th, according to the United Nations Office for the Coordination of Humanitarian affairs (UN OCHA).

Key numbers in need of aid. Source: UN OCHA

Key numbers in need of aid.
Source: UN OCHA

Click on the image below for a link to how best to donate towards aid efforts in Nepal.

More information:

Remembering the Colombia 1985 volcanic disaster

One of the most tragic volcanic events of the 20th century occurred in Colombia, in 1985, when an eruption of Nevado del Ruiz produced lahars that swept down river valleys and destroyed communities in its path. Over 20,000 people perished.

Mount Rainier and other volcanoes of the Pacific Northwest’s Cascade Range are similar to Nevado del Ruiz in many respects—massive amounts of snow and ice, a long history of lahars, and narrow valleys leading to populated areas. Could what happened at Nevado del Ruiz happen in the Pacific Northwest? And if it did, are we prepared?

In 2013, the US-Colombia Bi-national Exchange was created to help scientists, emergency managers and first responders in both countries to learn from the events in Colombia and to work toward improving disaster preparedness in communities located near volcanoes. The Exchange allows the Colombian officials to observe and learn about U.S. emergency response systems and for U.S. personnel to absorb the hard-earned lessons from the Colombians’ experiences with volcanic crises.

Scientists, decision-makers, emergency officials, community leaders, teachers, parents, students—everyone has a responsibility to prepare for the next eruption. Your role in preparedness begins with learning about the hazards where you live, work or go to school, evacuation routes and how to access information during a crisis. Ask local and state emergency officials and schools about their plans and be ready to follow their guidance. Finally, gather basic emergency provisions and create a plan to reunite with family members if you are separated. The volcano may erupt, but the tragedy doesn’t have to happen. And that is the point.

Disaster Charter activated for Villarrica volcano


A Red Alert has been declared in southern Chile after an eruption at Villarrica Volcano this morning.

Over two thousand people were evacuated from Pucon, and another thousand from Panguipulli, two communities close to the volcano.

While no one has been harmed in the eruption, the situation will continue to be monitored for any further eruption. The ash from the volcano could also pose a hazard to health. Meteorologists currently expect the ash cloud to be blown south and across remote parts of Argentina.

disaster_charterThe Disaster Charter is an agreement between international satellite and remote sensing agencies to provide free access to data and resources to help mitigate the effects of disasters on human life and property.

The Charter can be activated by any national disaster management authority. The activation for Villarrica was requested by the  Chilean agency responsible for civil protection (ONEMI, Oficina Nacional de Emergencia del Ministerio del Interior y Seguridad Pública).

For updates of the ongoing activity check the latest status reports from ONEMI, Chile. Also, follow #Villarrica on twitter for social media updates and more images of the current activity.


Natural hazards education in the Himalayas

Natural hazards education in the Himalayas

It’s a big month as the Geology for Global Development team embark on a major natural hazards education and sustainable development project in the Himalayas.

The project (part of a broader sustainable development project in the Himalayas) will be aiming to:

  1. Share our knowledge and expertise,
  2. Learn from others about aspects of best practice in both understanding science and understanding culture and social development,
  3. Identify practical skills development opportunities for students in the UK.

CGS academics are also involved with this project. Professor Tim Wright will be giving a keynote lecture at the conference in India later next week and Ekbal Hussain has contributed to a booklet that will be used to teach school children about natural hazards in the Himalaya region (above image).

Read more about the project here:


EGU 2014: The Landscape Detectives – Searching for prehistoric earthquakes

20140429-103457.jpgThe annual European Geoscience Union meeting is the largest conference gathering of geoscientists in Europe. Held in the historic city of Vienna, the meeting brings together a diverse range of scientists, students and professionals to share and exchange their research and ideas.

Many CGS academics and students from the University of Leeds are attending this year’s event. For the next week or so I’ll be writing a few short posts about some of the talks that catch, my eye from the Natural Hazards sessions. The first in the EGU series of posts is about playing detective with the landscape and is based on a talk given by COMET+ scientist Richard Walker.

Earthquakes are caused by the sudden release of energy by movements along large fractures in the Earth called faults. These events release a lot of seismic energy that spreads away from the fault. These are what causes damage to buildings and the landscape. Earthquakes can be very destructive events, as we saw in 2010 when a magnitude 7.1earthquake in Haiti killed almost 230,000 people!

An earthquake rupture preserved in the landscape in Mongolia. Image courtesy of Richard Walker.

An earthquake rupture preserved in the landscape in Mongolia. Image courtesy of Richard Walker.

It is important to understand the history of earthquakes along large faults if we are to accurately understand its behaviour and be able to make reliable forecasts of the hazards it might pose. However, the historical record of past activity on large faults is very sparse. Particularly in regions around Central Asia where populations have historically been small and/or nomadic.

This is where the landscape detectives come in. Every large earthquake results in movements along faults. Very often these movements are preserved in the landscape. This might be in the form of an uplifted river terrace, a diverted stream, an offset hill etc.

The landscape detectives, or geomorphologist to use the technical term, hunt for these clues and gather evidence for past movements along faults and try to determine the size of the movements and when it occurred. Using these they can give an estimate of the size of the earthquake that caused the event and more importantly add constraints on how fast the fault is moving. All these are are vital if we are to understand the fault and forecasts it’s behaviour in the future.

If you would like more information be sure to send us an email. I will write a more detailed feature on the actual techniques used by geomorphologists to untangle the earthquake history from the landscape after the conference.



From Science to Action: Lessons learnt from Haiti

Eric Calais

Eric Calais

Recently we had our first joint Climate and Geohazard Services (CGS) and Institute of Geophysics and Tectonics (IGT) seminar at the University of Leeds.

Our invited speaker was Eric Calais who was the U.N.’s Geophysicist on the ground after the 2010 Haiti earthquake. This is a short summary of some of the topics discussed in his seminar.

Science and scientists are needed on the scene of disaster risk reduction – Eric Calais

Haiti and indeed all the Caribbean countries are exposed to many numerous hazards including earthquakes and hurricanes. Of these the most reliable are hurricanes which hit the region like clockwork every summer. However earthquakes are less regular and often occur after much longer time intervals. So when it comes to hazard mitigation hurricanes trump earthquakes!

Eric started his talk with an introduction to the tectonics of the Haiti region. The countries largest city, Port-au-Prince lies about 20 kilometres north of a major strike slip fault called the Enriquillo Fault. Eric, working in Haiti earlier in his career, had predicted the fault had a chance of storing enough energy which if released all at once will result in a magnitude 7.1 earthquake.

Earthquakes are not new to Haiti. There is abundant evidence for historic ruptures including one that was recorded by British colonist in the seventeen hundreds. However due to the long recurrence time of such events the human memory of these events gradually gets lost. Therefore, the inhabitants of Port-au-Prince were not prepared when a magnitude 7.0 earthquake shook the country on the 12th January 2010.

Shake and damage map of the 2010 earthquake. Source: BBC

Shake and damage map of the 2010 earthquake. Source: BBC

The resulting devastation took the lives of nearly nearly 316,000 people according to Haitian Prime Minister Jean-Max Bellerive and displaced nearly a million people from their homes.

The second part of Eric’s talk focused on his experiences working with the U.N. as the chief geophysicist on the ground immediately after the earthquake.

The first important lesson learnt from Haiti is that the impacts from natural disasters are amplified by socio-economical and political issues.

UN aid in Haiti. Source:

UN aid in Haiti. Source:

It is clear that a government needs to find a balance between the gains from increased mitigation with the costs needed to achieve such mitigation levels. The maximum mitigation achievable with the minimum cost is generally the prefered option, especially for developing countries. But these decisions need to made with due consideration to the types, expected magnitude and repeat interval of each individual hazard.

The U.N. is well aware that building resilience is the key to maintaining development and reducing loss from natural disasters.

An important goal for the U.N. is to offer advice and embed clear resilience and mitigation strategies into governmental policy and ensure that these policies are effectively enforced.

However much of the U.N. data on human exposure to natural disasters are not entirely accurate and often out of date. Worryingly there appears to be no clear procedure for updating this information. Improving resilience becomes much more difficult without knowing the nature of the hazards faced. It is clear that the U.N. needs to invest in resources to update key data tables such as exposure and vulnerability; combining information from industry, especially the re-insurance sector, and outputs from the scientific community.

Post earthquake. Source:

Post earthquake. Source:

Most of the U.N. members of staff are non-scientists. Therefore, many of the on-the-spot decisions during disasters are made without a proper understanding of the underlying science.

It is clear that the scientific community have not been paying enough attention! We as scientists need to be more involved with the issues of disaster risk reduction. Scientists understand the hazards, the risks involved and to some extent what needs to be done. We just need to step forward and be more involved.

Eric ended his talk with the following call to arms:

“The gap between science products and practitioners of risk reduction requires someone to make the first step; scientists are in the best position [to take this step].”

Further Reading:



Plight of the Bangladeshi


Lying on the floodplains of the mighty Ganges, Brahmaputra and Meghna rivers Bangladesh is a rich, fertile land. These giant river systems meet in the centre of the country and flow together into the Bay of Bengal which, at over 1600km wide, is the largest delta system in the world.

Flood potential map of Bangladesh. Source

Flood potential map of Bangladesh. Source

Rising Sea Level

Bangladesh is often cited as one of the countries that will be most affected by rising sea levels from human induced climate change and with good reason. Two thirds of the country lies less than 5m above of sea level. With vast regions to the south much less than a 1m above sea level. The Intergovernmental Panel on Climate Change (IPCC) 2007 report claimed that just 1m rise in sea level could directly expose nearly 14 million people and result in potentially 20% land loss! Although it is unlikely that the actual figures will be so high, the numbers are worrying large.


Most of the country receives on average more than 2.5m of rainfall a year, 80% of which falls in about 4 months during the peak monsoon season. Contrast that with the UK, which in 2012 had an annual rainfall of less than 1.3m. Combine this with poor flood defences and you have large annual floods. The flood waters bring nutrient rich clays and silts from the high Himalayas and deposit them on the river floodplains during these events. These rich soils produce vast harvests of rice and other crops. Not surprising then that agriculture is the most common livelihood.

Floods in Bangladesh. Source NASA

Floods in Bangladesh. Source NASA

However floods, once welcomed by farmers and their families are now harbingers of disaster. Human induced climate change has resulted in more erratic monsoonal weather patterns with often larger the normal volumes of water being delivered in shorter time intervals. The resulting floods have had devastating effects on the Bangladeshi people. In 2012 three large floods hit the country in swift succession between the months of July and September directly affecting more than 5 million people. These are now a common annual occurrence.


Bangladesh is also annually subject to devastating tropical cyclones, tidal bores and tornadoes. Some of the worst natural disasters in recorded history were results of cyclonic storms in the Bengal region. Among them, the 1970 Bhola cyclone which claimed over 500,000 lives! Worryingly new research into the effects of human induced climate change has shown that large cyclonic storms will become a more common occurrence in the years and decades to come.


The foothills of great Himalayan mountain belt has historically been the location of many large earthquakes. Earthquakes in the continents tend to be more infrequent compared to regions such as Japan and California. However this makes them more unpredictable and often unexpected. But when one does occur it can result in significant ground shaking. The 1897 magnitude 8.1 and 1950 magnitude 8.7 Assam earthquakes were two of the biggest to hit the region in recent times.

Aftermaths of an earthquake. Source

Aftermath of an earthquake. Source

Bangladesh has a population of over 160 million and among the highest population density of any country in the world. With the majority of the country built on river floodplains combined with widespread corruption and ignorance a large earthquake could quite possibly result in the greatest natural calamity to have ever hit the country!

So what can we as earth scientists do?

Bangladesh needs to increase its resilience if its people are to survive the multitude of natural hazards they face. Earth scientists are well placed to understand the risks involved from these hazards and can play a key role in all aspects of building a resilient infrastructure.

Climate science research is ongoing and needs to continue to better understand the affect human induced climate is having and will have on the annual monsoon. This knowledge then needs to be translated into rainfall variation and flooding potentials. The socio-economic issues of a rising sea level can be addressed by the sustainability community. How can we feed millions of people displaced as a direct result of climate change? How can we provide clean drinking water in flood prone regions? The hydrogeologists and geochemists can help find sustainable clean, arsenic free water sources for drinking and farming during the non-monsoon season. The seismologists and earthquake scientists can better assess the seismic risk; produce more accurate hazard maps and importantly identify the active faults within the region.

These are to name but a few of the ways earth scientists can get involved. I believe it is our moral duty to translate the practical aspects of our science into real benefits for people. Only then can we ever hope of helping these people.




Further Reading:

Earthquake hazard for Istanbul

Istanbul is an ancient and beautiful city with a long history at the centre of major empires including the Roman, Byzantine, Latin and Ottoman. It is a city inundated with rich culture and history. In 2010 it was named a European Capital of Culture making it the world’s tenth most popular tourist destination. Home to over 13 million people it is also one of the most densely populated cities in Turkey.

A building destroyed in the 1999 Izmit earthquake

A building destroyed in the 1999 Izmit earthquake

But this thriving and seemingly indestructible city sits on a loaded spring: The North Anatolian Fault. The most active and earthquake prone fault system in Turkey and the source of the 1999 magnitude 7.4 earthquake that killed nearly 18,00 people in the city of Izmit.

The North Anatolian Fault is about 1300km long running along the entire length of northern Turkey, from the Aegean Sea to the west to Lake Van to the east.

It has been known for a while now that earthquakes on the fault tend to follow a successive sequence, i.e. an earthquake rupture will often occur in the section of the fault proceeding the last rupture. The current sequence started in 1939 with the magnitude 7.9 Erzincan earthquake and has been progressing to the west in a series of 12 large earthquakes.

Researchers in 1997 used this observation to successfully predict the location of the 1999 Izmit earthquake (if not the exact time). Worryingly the Izmit earthquake ruptured less than 100km to the east of Istanbul. Further work has led other researchers to predict a major earthquake, possibly another magnitude 7.4 in the Istanbul region within the next 20 years!

Current westward progression of earthquakes along the North Anatolian Fault.

Current westward progression of earthquakes along the North Anatolian Fault.

So what can we do? Firstly, we need to better understand the science behind the cause of earthquakes in this region. The FaultLab project based at the University of Leeds involves research into the nature of the North Anatolian Fault and the surface deformation during various stages of the earthquake cycle. A greater understanding of the fault system can be used in forecasting models to give a better idea of the seismic risk.

Secondly, more engineering work needs to be done to reinforce vulnerable buildings which would collapse in the event of ground shaking. In May 2012 the Turkish government passed a new Urban Transformation Law which stated that all buildings that did not conform to current earthquake hazard and risk criteria will be demolished and rebuilt.

Is it too late?

Is it too late?

This effectively means nearly 7 million buildings throughout Turkey will be rebuilt to current earthquake standards over the next two decades! This massive project is expected to generate over USD 500 billion worth of construction industry over the next decade. Only last month, (February 2013) work began in Istanbul.

A new rail line currently under construction which runs beneath the Bosphorus Sea and links the east and western parts of the city will also be able to withstand moderate to high intensity shaking.

But the key question is: will Turkey and Istanbul in particular be able to finish all this redevelopment before the next major earthquake?

For all our sake, I certainly hope so!


More information:
[1] Progressive failure on the North Anatolian fault since 1939 by earthquake stress triggering, 1997, Geophysical Journal International, v 128, pp 594-604
[2] Parsons, T., Shinji, T., Stein, R. S., Barka, A. A., Dietrich, J. H.; Heightened Odds of Large Earthquakes Near Istanbul: An Interaction-Based Probability Calculation, 2000, Science, v 288, pp 661-665