̽��ֱ�� of Cambridge - James Jackson

Be prepared: it’s impossible to predict an earthquake

jg533 — Tue, 09 Nov 2021 16:11:45 +0000

A collaboration across many countries has shifted the focus away from short-term earthquake prediction towards increasing resilience. ̽��ֱ��results are saving lives.

Earthquakes without frontiers

sc604 — Mon, 26 Oct 2015 13:31:11 +0000

̽��ֱ��Ganges is India’s most iconic river, flowing from the Himalaya to the Bay of Bengal, and its massive river basin is one of the most fertile and densely populated regions in the world. ̽��ֱ��Ganges flows through 29 cities with a population over 100,000, 23 cities with a population between 50,000 and 100,000, and close to 50 towns.

But someday – perhaps tomorrow or perhaps in 100 years – a massive earthquake will hit the region, and the consequences could be catastrophic: as many as a million lives in the Ganges river basin could be at risk, primarily because buildings have not been constructed to be earthquake resilient, despite the fact that the relevant building codes are in place.

Of course, earthquakes don’t respect borders, and India is not alone in being at risk due to poorly constructed buildings. Northern India lies in the Alpine–Himalayan earthquake belt, which stretches from the Mediterranean to the Pacific. It is the second-most seismically active region in the world, and responsible for around 20% of the world’s largest earthquakes. ̽��ֱ��belt is being created by ongoing plate tectonics: as the African, Arabian and Indian plates continue to move northwards, they collide with the Eurasian plate.

̽��ֱ��earthquake belt includes the most famous of the great trade routes, the Silk Road, which follows the edges of deserts and mountains, and high plateaus like Tibet. ̽��ֱ��landscape of the Silk Road has been shaped by earthquakes over millions of years: forcing mountains upwards and making life in the desert possible by controlling where water comes to the surface.

As the earthquake faults grind rocks together they make an impermeable clay, which often forces water to the surface along spring lines, determining where people live. To the casual observer, it seems as if the major earthquakes in this part of the world often seem to ‘target’ towns and cities but, in reality, people are often simply living where the water is, which is also where earthquakes happen.

Between 2 and 2.5 million people have died in earthquakes since 1900. Approximately two thirds of those deaths occurred in earthquakes in the continental interiors – places like northern India. Over that time, advances in the scientific understanding of earthquakes have been translated into impressive resilience in places where the hazard is well understood, which are mainly on the edges of the oceans. Comparable advances have not, however, taken place in most parts of the continental interiors, where the hazard is still much less well identified and poorly understood.

“Earthquake science has progressed so that we’re now much better at recognising the signals in the landscape that tell us whether a particular place is dangerous,” says Professor James Jackson, Head of Cambridge’s Department of Earth Sciences. “We can’t tell you exactly when an earthquake is going to happen, but we can say it will happen, not least because it’s happened before. If it’s happened before, it will happen again. What we can do, however, is to understand earthquakes better and use that knowledge to help make buildings safer.”

Four years ago, with funding from the Natural Environment Research Council, Jackson and colleagues from other universities in the UK established Earthquakes Without Frontiers (EWF), an international partnership bringing together earthquake scientists from across the great earthquake belt, from China to Italy, in order to share expertise. “But it soon became clear that the project was about much more than earthquake science, and the real issue was how to translate science into effective policy, which requires an understanding of the social context in which people live,” says Jackson.

With additional funding from the Economic and Social Research Council, EWF expanded to include social science and policy dimensions. ̽��ֱ��project, which runs until 2017, has three overarching objectives: to increase knowledge of earthquake hazards across the region; to establish greater resiliency against these hazards; and to establish a well-networked interdisciplinary partnership to support local earthquake scientists. Within Asia, there are more than 50 national level stakeholders who are working with EWF on earthquake risk reduction.

Across much of the earthquake belt, people live in large cities, mostly in poorly built apartment blocks and buildings that have not been designed to withstand earthquakes. Large cities such as Tehran, Almaty and Bishkek have all been destroyed multiple times by earthquakes, and it’s only a matter of time before the next one hits. ̽��ֱ��problem that EWF faces is convincing the public and policy makers of the importance of making towns and cities more earthquake resilient.

“In these big cities, everyday life is difficult enough: they’re very congested, they have huge problems with traffic, air quality, water quality, food supply and poverty,” explains Jackson. “And quite understandably, the risk of an earthquake seems quite remote compared to daily worries. But that doesn’t make the threat go away.”

“We face two main problems: the first is that there is a lack of awareness of the fact that seismologists cannot predict earthquakes – it’s just not something we are able to do or will be able to do,” says Dr Supriyo Mitra of the Indian Institute of Science Education and Research Kolkata. Mitra obtained his PhD at Cambridge, and is now one of the key Indian academic collaborators on the project, primarily working in Indian-administered Kashmir. “ ̽��ֱ��other problem is that there is a lot of resistance to making buildings safe. It is an additional cost, but it’s a necessity and we need to get that across to people.”

Perhaps the most important change that can be made to increase earthquake resilience in these areas is the enforcement of building codes. ̽��ֱ��building codes in Los Angeles and Tehran are similar, but the difference is that in Los Angeles, most buildings are constructed according to those codes, while in Tehran most are not, so as a result, Los Angeles is highly resilient to earthquakes, while Tehran remains very vulnerable.

“Enforcement comes not just from legal enforcement, but education,” adds Jackson. “People are really starting to realise that this is important. And once you educate the public, it rises up the agenda because the public insists that it does.

“There are going to be around a billion new homes built across Asia over the next 10 years – let’s build them so they are safe.”

̽��ֱ��Alpine–Himalayan belt, which stretches from the Mediterranean to the Pacific, is one of the world’s most seismically active regions. Now, a combination of earth science, social science and education is being used to help the region become more resilient to earthquakes, protecting lives and property.

We can’t tell you exactly when an earthquake is going to happen, but we can say it will happen, not least because it’s happened before. If it’s happened before, it will happen again.

James Jackson

Timothy Smith, U.S. Navy

̽��ֱ��city of Muzafarabad, Pakistan lays in ruins after the 2005 Kashmir earthquake that hit the region.

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Cambridge people named in the Queen's Birthday Honours list

th288 — Sat, 13 Jun 2015 05:10:01 +0000

Professor Harshad Kumar Dharamshi Bhadeshia FRS FREng (pictured centre) is the Tata Steel Professor of Metallurgy in the Department of Materials Science and Metallurgy and Director of the SKF Steel Technology Centre. His work is focused on transformation theory, which is concerned with the arrangement of atoms in a solid, in order to enable the invention of new iron alloys. He has been appointed a Knight Bachelor for services to Science and Technology.

Professor Christopher Munro Clark (pictured right) is the Regius Professor of History. His research work is centred on the history of 19th-century Germany and continental Europe. He has published numerous studies and books relating to the political and cultural history of religion, Kaiser Willhelm II, and the history of Prussia. He has been appointed a Knight Bachelor for services to British German relations.

Archibald Hugh Duberly, CBE is the Lord-Lieutenant of Cambridgeshire and a Senior Member of Wolfson College. He has been appointed a KCVO.

Professor Christopher Aidan Gilligan (pictured left) is the Head of the Epidemiology and Modelling Group in the Department of Plant Sciences. His work is focused on developing and testing a theoretical framework to understand the mechanisms that control invasion, persistence, scaling and variability of epidemics within changing agricultural and natural landscapes. He is also a Trustee of the Natural History Museum, by Prime Ministerial appointment. He has been appointed CBE for services to plant health in the field of epidemiology.

Professor Elizabeth Anne Howlett Hall is Professor of Analytical Biotechnology and Head of the Cambridge Analytical Biotechnology Group in the Department of Chemical Engineering and Biotechnology. Her research work is into heterogenous analytical systems with a primary focus on molecular sensors and directed towards environmental, medical and industrial application. She is also the Chair of Disability Snowsports UK. She has been appointed CBE for services to higher education and to sport.

Professor Anthony John Holland is Professor of the Psychiatry of Learning Disabilities and Head of the Cambridge Intellectual and Developmental Disabilities Research Group in the Department of Psychiatry. His main areas of research include the relationship between genetic syndromes and associated psychiatric and behavioural disorders, and clinico-legal studies. He is also Chair in Learning Disabilities at the Health Foundation, Fellow and Vice-President of the International Association for the Scientific Study of Intellectual Disability, President of the UK Prader-Willi Association, and President of Cambridge MENCAP. He has been appointed CBE for services to psychiatry.

Professor James Anthony Jackson FRS is Professor of Active Tectonics and Head of the Department of Earth Sciences. His work exploits techniques in earthquake source seismology, geomorphology, space geodesy and remote sensing to examine how the continents are deforming today on all scales: from the details of the fault rupture in single earthquakes, to how that faulting has created the local geomorphology and structure, to how regional fault patterns and motions can accommodate deformation of vast continental areas. He is also part of the Dynamic Earth and Geohazards Group, and the lead Principal Investigator on the Earthquakes Without Frontiers Project – a joint NERC-ESRC consortium supporting a partnership of physical and social scientists working to help increase resilience to earthquakes in countries in Asia. He has been apointed CBE for services to environmental science.

Seven distinguished members of the ̽��ֱ�� have been named in the Queen’s Birthday Honours list announced today.

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Yes

Scientists explain scale of Japanese tsunami

amb206 — Fri, 24 Aug 2012 09:35:54 +0000

Scientists at Cambridge ̽��ֱ�� have developed a model that may show why some tsunamis – including the one that devastated Japan in March 2011 – are so much larger than expected. ̽��ֱ��Japanese tsunami baffled the world’s experts as it was far bigger than might have been anticipated from what is known about the deep sea earthquakes that create long waves out in the ocean.

In a paper published today (24 August 2012) in the journal Earth and Planetary Science Letters, Professors Dan McKenzie and James Jackson of Cambridge’s Department of Earth Sciences describe for the first time the added factor that may have made this tsunami so severe: a huge collapse of soft material on the sea bed resulted in a far greater movement of water than would have been caused by the earthquake alone.

Tsunamis occur when an earthquake rapidly changes the shape of the sea floor, displacing the water above it. ̽��ֱ��earthquake itself is the abrupt rupture of a fault surface separating rocks that have steadily been bending like a loaded spring, before suddenly overcoming friction and slipping, releasing the elastic energy. In the case of the Japan earthquake, the fault is the plate boundary, allowing the Pacific sea floor to slide beneath Japan. ̽��ֱ��wave formed at the sea surface as the sea floor moves can cause untold damage when it hits shore.

“As the plates move against each other, the rocks on their boundaries slowly bend under the pressure, until they eventually crack and slide on faults. When they do, there is an upwards and outwards movement that takes just a few seconds: a movement of 10 metres is a large earthquake and out at sea this causes a tsunami,” said Professor Jackson.

“But data from the Japanese earthquake show a movement of more than 60 metres. Rocks can bend - but they cannot bend to that extent and, anyway, the rocks that moved were sloppy sediments with little strength. This suggests that something else was taking place to increase the movement several fold. It was this massive movement that caused the tsunami that swamped the coast of Japan and beyond with such terrible consequences.”

Important advances in technologies for monitoring movements on the sea bed, plus a huge investment by the Japanese government, mean that the world’s scientific community has access to an unprecedented level of data about what happened in March 2011 some seven km under the sea and around 70 km off the coast of Japan.

By interpreting data gathered in the lead-up to and aftermath of the Japanese tsunami, as well as during the event itself, the Cambridge scientists have shown that the squeezing together of two plates in the earth’s crust not only resulted in a fracture but also caused a massive collapse of the debris that had built up on the sea bed as tectonic movements scraped loose sediment into an unstable wedge.

“When the wedge of material collapsed, the leading edge split off and shot forward a bit like a pip shooting out of a giant pair of tongs. In essence, what happened was a release of both the elastic energy stored in the rocks and the gravitational energy contained in the wedge-shaped build-up of debris,” said Professor Jackson.

̽��ֱ��extra movement of the sea bed at the toe of the wedge enhanced the shape of the huge wave created at the surface of the sea, which travelled towards Japan.

̽��ֱ��research throws a light on other unusually large tsunamis that have long puzzled scientists, including those that struck Nicaragua in 1992, Sumatra in 2004, and Java in 2006. A comparison of data from these events with that from the recent Japanese tsunami reveals that they have much in common, strongly suggesting that these disasters too occurred as a result of the release of gravitational as well as elastic energy.

“These events share a number of unusual features, including large displacements, suggesting that they resulted partly from the collapse of debris. We hope that our research represents a step forward in understanding how large tsunamis occur and in what circumstances they are likely to happen,” said Professor Jackson.

Tsunamis are caused by earthquakes under the seabed. Some tsunamis – including the disaster that hit Japan last year – are unexpectedly large. Cambridge scientists suggest that their severity is caused by a release of gravitational energy as well as elastic energy.

We hope that our research represents a step forward in understanding how large tsunamis occur.

Professor James Jackson

REUTERS/Mainichi Shimbun

A wave approaches Miyako City from the Heigawa estuary in Iwate Prefecture

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Yes

Tweeting disasters

ns480 — Wed, 12 Oct 2011 09:52:45 +0000

Professor John Preston, who is based at the ̽��ֱ�� of East London’s Cass School of Education, will tell the ‘Violent Nature’ Research Councils UK debate that Twitter and Facebook have been credited with being able to pick up advance signals of disasters. However, it is only in retrospect that the significance of the signals can be ascertained.

̽��ֱ��debate focuses on whether governments, scientists and aid agencies can manage the risks of living in potentially lethal locations. Other speakers include Professor James Jackson from the ̽��ֱ�� of Cambridge, Daniel Walden, policy adviser for disaster risk reduction at Save the Children UK and Dr Andrew Collins, reader and director of the Disaster and Development Centre at Northumbria ̽��ֱ��. It will be chaired by James Randerson, the Guardian's science and environment editor.

Professor Preston is the leader of a two-year cross-disciplinary research programme, supported by the the Research Councils UK Global Uncertainties Programme, which began in 2010 and seeks to uncover how the likes of Twitter and Facebook could save lives in the event of a national crisis such as a terrorist attack or natural disaster.

He says that where Twitter in particular works well is in correcting information and countering false rumours. “There is an inherent self-correcting bias in Twitter which is like the scientific process. When someone posts it sifts the evidence for and against and the more current information countervails anything that came before,” says Professor Preston, whose book Disaster Education is out early next year.

He adds: “Social networks can be used for malicious reasons to spread rumours by targeting false information at a few super-connected people. Information spread this way would take longer to correct.”

Professor Preston says: “Part of the reason authorities are put off using social media to spread information during disasters is that it can appear quite uncontrollable since information sharing after disasters tends to be followed by a period of emotional reflection on what it means. Emotion is very important in social media. It's not just about information. People use it quite creatively which can make it a little bit uncontrollable.”

̽��ֱ��research programme is looking at how to prepare the UK better for disasters, through, for instance, cell broadcasting and community education, and is looking at lessons that can be learnt from the past.

̽��ֱ��Violent Nature debate will take place at the McCrum Lecture Theatre, Corpus Christi College, Cambridge from 8-9.30pm on 25^th October.

Social networks like Twitter cannot help prevent disasters, but can quickly correct misinformation resulting from false rumours preventing possible further loss of lives, a leading researcher will tell a public debate on 25th October at the Cambridge Festival of Ideas.

Emotion is very important in social media. It's not just about information. People use it quite creatively which can make it a little bit uncontrollable.

Professor John Preston

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Search and rescue

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