How can cities protect metro systems from terrorism?

Wreaths of flowers on the ground near the Maalbeek subway station in Brussels after a 2016 terrorist attack. Image: Getty.

Since the start of the millennium, hundreds of passengers have been killed and thousands injured by bombings on metro rail systems. These systems are particularly vulnerable to terrorist attacks using improvised explosive devices (IEDs), a weakness which has been exploited by more than 150 terrorist organisations – ranging from ultra-left extremists to religious fanatics – to target commuters in 64 different countries over the past four decades.

Madrid’s Cercanias commuter train system was hit in 2004, London’s Underground in 2005, Mumbai’s suburban rail network in 2008 and Moscow’s metro in 2010. More recently, bombings took place in Brussels in 2016 and again on the London Underground at Parsons’ Green Station in September 2017.

There are certain factors which make metro rail systems particularly vulnerable to attacks like these – but there are also several measures that authorities can take to make them safer.

Security measures are weak at most train stations – and there’s a high concentration of people. This makes them prime targets for terrorists looking to carry out mass casualty attacks using IEDs. IEDs have been a weapon of choice for three main reasons: they’re easy to acquire, there’s a low risk of detection and the potential impact is huge.

IEDs are relatively inexpensive to build, and the internet has emerged as a valuable source for terrorists to share detailed instructions on how to assemble a wide range of bombs. Once put together, IEDs can be smuggled onto packed commuter trains to cause mass casualties.

Installing airport-style security checks at train stations could prevent attackers armed with IEDs from entering. But this presents obvious difficulties: metro rail systems are designed to be used by millions of passengers every day. People would resent long waits in security queues multiple times a day to complete their commute.

Mad rush, Manila. Image: FotoGrazio/Flickr/creative commons.

Owing to their function, metro rail projects are conceived as open architecture systems. This means that, in the design phase, emphasis is placed on facilitating the movement of passengers. Every care is taken to minimise the presence of bottlenecks (other than those created by shops and fare collection gates) that can inhibit movement, cause delays and create safety concerns, brought about by overcrowding. This open design makes it easier for terrorists to enter, plant explosive devices hidden in bags or backpacks and make their escape afterwards.

Metro rail systems are also vulnerable because of the inherent predictability in the way they operate. It is easy for terrorists to work out when trains are most crowded, in order to cause a large number of casualties. This may explain why the attacks on the London Underground in 2005 and 2017 both took place during the rush hour.


A stronger response

The response of security agencies to this threat has varied around the world. In London, the emphasis is on covert measures. Police rely on intelligence-led operations to disrupt plots at the planning stage, while a vast network of CCTV cameras is used for surveillance to identify suspicious behaviour.

At the other end of the spectrum, security personnel in Beijing, Delhi and Moscow scan every bag for explosives and pat down every passenger before they can start their commute. This approach comes at a cost, as waiting times in security queues can stretch up to 20 minutes during the rush hour.

Across the world, it’s becoming increasingly common for railway companies and police to rely on ordinary railway employees such as train drivers, station managers and platform managers to perform a security role by identifying suspicious objects and individuals and reporting them to authorities.

Training railway staff in a security role can lead to “target hardening”: in other words, it increases the effort required on part of terrorists to attack metro rail systems and raising their chances of getting caught. The challenge for rail companies has been that the security role creates an additional burden for staff, which could lead to errors in both the security checks and their conventional role.

Innovative technology and design solutions are also being tested, to better secure metro rail systems against terrorist attacks. For example, provisions are made at the design stage of stations to include potential checkpoints, where baggage scanners can be installed to check passengers when police receive specific warnings.

The ConversationThere are nearly 200 operational metro rail systems worldwide – and new ones are under construction at a rapid pace . They provide a fast, affordable and environmentally friendly means of transport to large sections of population and have become an essential feature of cities across the world. Now, security agencies, railway operators and engineering companies must come together to protect these systems – and the people who use them – from the threat of terrorism.

Kartikeya Tripathi, Teaching Fellow, Security and Crime Science, UCL and Hervé Borrion, Associate Professor in Security and Crime Science, UCL.

This article was originally published on The Conversation. Read the original article.

 
 
 
 

Here’s why we’re using a car wash to drill into the world’s highest glacier on Everest

Everest. Image: Getty.

For nearly 100 years, Mount Everest has been a source of fascination for explorers and researchers alike. While the former have been determined to conquer “goddess mother of the world” – as it is known in Tibet – the latter have worked to uncover the secrets that lie beneath its surface.

Our research team is no different. We are the first group trying to develop understanding of the glaciers on the flanks of Everest by drilling deep into their interior.

We are particularly interested in Khumbu Glacier, the highest glacier in the world and one of the largest in the region. Its source is the Western Cwm of Mount Everest, and the glacier flows down the mountain’s southern flanks, from an elevation of around 7,000 metres down to 4,900 metres above sea level at its terminus (the “end”).

Though we know a lot about its surface, at present we know just about nothing about the inside of Khumbu. Nothing is known about the temperature of the ice deeper than around 20 metres beneath the surface, for example, nor about how the ice moves (“deforms”) at depth.

Khumbu is covered with a debris layer (which varies in thickness by up to four metres) that affects how the surface melts, and produces a complex topography hosting large ponds and steep ice cliffs. Satellite observations have helped us to understand the surface of high-elevation debris-covered glaciers like Khumbu, but the difficult terrain makes it very hard to investigate anything below that surface. Yet this is where the processes of glacier movement originate.

Satellite image of Khumbu glacier in September 2013. Image: NASA.

Scientists have done plenty of ice drilling in the past, notably into the Antarctic and Greenland ice sheets. However this is a very different kind of investigation. The glaciers of the Himalayas and Andes are physically distinctive, and supply water to millions of people. It is important to learn from Greenland and Antarctica, – where we are finding out how melting ice sheets will contribute to rising sea levels, for example – but there we are answering different questions that relate to things such as rapid ice motion and the disintegration of floating ice shelves. With the glaciers we are still working on obtaining fairly basic information which has the capacity to make substantial improvements to model accuracy, and our understanding of how these glaciers are being, and will be, affected by climate change.

Under pressure

So how does one break into a glacier? To drill a hole into rock you break it up mechanically. But because ice has a far lower melting point, it is possible to melt boreholes through it. To do this, we use hot, pressurised water.

Conveniently, there is a pre-existing assembly to supply hot water under pressure – in car washes. We’ve been using these for over two decades now to drill into ice, but our latest collaboration with manufacturer Kärcher – which we are now testing at Khumbu – involves a few minor alterations to enable sufficient hot water to be pressurised for drilling higher (up to 6,000 metres above sea level is envisioned) and possibly deeper than before. Indeed, we are very pleased to reveal that our recent fieldwork at Khumbu has resulted in a borehole being drilled to a depth of about 190 metres below the surface.

Drilling into the glacier. Image: author provided.

Even without installing experiments, just drilling the borehole tells us something about the glacier. For example, if the water jet progresses smoothly to its base then we know the ice is uniform and largely debris-free. If drilling is interrupted, then we have hit an obstacle – likely rocks being transported within the ice. In 2017, we hit a layer like this some 12 times at one particular location and eventually had to give up drilling at that site. Yet this spatially-extensive blockage usefully revealed that the site was carrying a thick layer of debris deep within the ice.

Once the hole has been opened up, we take a video image – using an optical televiewer adapted from oil industry use by Robertson Geologging – of its interior to investigate the glacier’s internal structure. We then install various probes that provide data for several months to years. These include ice temperature, internal deformation, water presence measurements, and ice-bed contact pressure.


All of this information is crucial to determine and model how these kinds of glaciers move and melt. Recent studies have found that the melt rate and water contribution of high-elevation glaciers are currently increasing, because atmospheric warming is even stronger in mountain regions. However, a threshold will be reached where there is too little glacial mass remaining, and the glacial contribution to rivers will decrease rapidly – possibly within the next few decades for a large number of glaciers. This is particularly significant in the Himalayas because meltwater from glaciers such as Khumbu contributes to rivers such as the Brahmaputra and the Ganges, which provide water to billions of people in the foothills of the Himalaya.

Once we have all the temperature and tilt data, we will be able to tell how fast, and the processes by which, the glacier is moving. Then we can feed this information into state-of-the-art computer models of glacier behaviour to predict more accurately how these societally critical glaciers will respond as air temperatures continue to rise.

The ConversationThis is a big and difficult issue to address and it will take time. Even once drilled and imaged, our borehole experiments take several months to settle and run. However, we are confident that these data, when available, will change how the world sees its highest glacier.

Katie Miles, PhD Researcher, Aberystwyth University and Bryn Hubbard, Professor of Glaciology, Aberystwyth University.

This article was originally published on The Conversation. Read the original article.