Between a Rock and a Hard Place

Charly Stamper

Charly completed a PhD in experimental petrology. She used to make pretend volcanoes; now she works in renewable energy. Charly tweets at @C_Stamper.

PhD interview preparation

The following post is written primarily for those who are applying for a PhD project where the funding is supplied by a research council, such as NERC. All PhD interviews are all different, and this post definitely won’t cover everything, but it should help you prepare for most eventualities.

If in doubt, go smart - but don't worry, you can spend the next three years wearing jeans and a hoody. Credit: Alex France

If in doubt, go smart – but don’t worry, you can spend the next three years wearing jeans and a hoody. Photo credit: Alex France

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Science Snap (#19): Angkor Wat, Cambodia

Sorcha McMahon is a third year PhD student in the School of Earth Sciences at the University of Bristol. Sorcha is investigating how strange igneous rocks called carbonatites may have formed, using both natural samples and high-pressure experiments.

The word Angkor is derived from the Sanskrit term Nagara meaning “Holy City”, and was the capital city of the Khmer. It consists of successive city foundations and temples constructed by the kings of three dynasties over a period of about 600 years. The site is most famous for Angkor Wat, the largest religious monument in the world, which has been a part of the Cambodian national flag since the first version was introduced circa 1863.

View of Angkor Wat, Cambodia. The temple is part of the Angkor World Heritage Site, established in 1992.

View of Angkor Wat, Cambodia. The temple is part of the Angkor World Heritage Site, established in 1992. Photo credit: Sorcha McMahon

Angkor Wat was constructed under the rule of King Suryavarman II (reigned AD 1113 – 1150), and built in the form of Mount Meru, home of the Hindu gods. The main temple incorporates 5 towers, representing the peaks of Mt Meru, and is surrounded by ~1×1 km walls (‘mountain ranges’) and a moat (‘ocean’). The temple was built as a place to worship ancestors and as a mausoleum to receive the cremated remains of individual kings.

The temple beautifully displays the classical style of Khmer architecture. Over 5 million tons of sandstone was used in the temple’s construction. Rocks were transported by raft along the Siem Reap river from Mount Kulen, ~ 40 km to the north east. Laterite, a clay formed by weathering of rocks in the tropics, was also used for internal structure. Large blocks were laid without mortar, and it’s likely that elephants, ropes, pulleys and bamboo scaffolding were all employed in the construction. Today, holes in the blocks can be seen (~2.5 cm diameter and 3 cm deep), probably used to aid lifting the blocks into place using metal rods. Angkor Wat was completed in around 40 years (the duration of the king’s reign), although a modern engineer estimated that it would take 300 years to complete Angkor Wat today!

Much of Angkor Wat’s sandstone surface was apparently once covered in gold, and other temples in the area were originally red (painted using tree resin). Bas-relief friezes (low relief images typical of Hindu-Buddhist arts in India and SE Asia) dominate the decoration. Imagery includes the king, his court, and iconographic scenes drawn from the Hindu religion. Apsaras (female spirits of the clouds and waters in Hindu and Buddhist mythology) and devatas, from the Hindu term for ‘Deva’ meaning deity, are abundant; there are more than 1796 depictions of devata in the present research inventory.

Intricate bas-relief on the ceiling and walls inside Angkor Wat. Remnants of the original red colour has been partially preserved.

Intricate bas-relief on the ceiling and walls inside Angkor Wat. The original red colour has been partially preserved. Photo credit: Sorcha McMahon

Sandstone carving of devata at Angkor Wat. Credit: Sorcha McMahon

Sandstone carving of devata at Angkor Wat. Photo credit: Sorcha McMahon

Life and death, and money

Mel Auker is an Earth Sciences PhD student in the School of Earth Sciences at the University of Bristol. A mathematician by trade, Mel’s PhD uses numerical approaches to better understand past, present, and future global volcanic hazard and risk.

The recent tragedy at Sinabung volcano, Indonesia, bought some interesting thoughts to light amongst some members of the volcanology group at Bristol. There were comments regarding the decision by the authorities to allow people to return to their homes (you can see James Hickey’s perspective here). In an ideal world, I’m sure we are all agreed that the risks of volcanoes and their eruptions would be fully mitigated, and fatalities and financial losses would be zero.

Sadly, there is no such ideal. The reality is one of limited resources and a need to balance the benefits and costs of risk reduction to society. Personally, I find the concept of attaching a value to a life a difficult one. But policy makers calculate the Value of a Statistical Life (VSL) in order to make rational risk-reduction decisions at the societal level. The VSL is defined as the value an individual places on a marginal change in their likelihood of death, i.e. the price an individual is willing to pay for a small decrease in the likelihood of their death. In theory, the VSL could be calculated as follows:

“Suppose each person in a sample of 100,000 people were asked how much he or she would be willing to pay for a reduction in their individual risk of dying of 1 in 100,000, or 0.001%, over the next year. Since this reduction in risk would mean that we would expect one fewer death among the sample of 100,000 people over the next year on average, this is sometimes described as “one statistical life saved.” Now suppose that the average response to this hypothetical question was $100. Then the total dollar amount that the group would be willing to pay to save one statistical life in a year would be $100 per person × 100,000 people, or $10 million. This is what is meant by the value of a statistical life.” US Environmental Protection Agency

The price of a life

What price on a life? Image credit: Mel Auker

In practice, VSL calculations are often based on the payments people receive for risks they voluntarily take in their day-to-day life, by examining the wages paid in different jobs. After controlling for all the other factors that may affect wages (such as location and skill level), the remaining wage variation can be attributed to compensation for the risk of death. This value can be used in the same way as in the example above to calculate the VSL. Another similar method involves comparing the price people are willing to pay for goods of differing safety standards, such as cars.

The outcomes of VSL calculations are varied, but Miller (2000)1 presents a review of 39 US and 7 UK studies and produces data-based estimates of $3.472m and $2.281m in 1995 US dollars for these countries, respectively. There are insufficient data for Indonesia, but using a series of assumptions and proxy values, Miller estimates a Indonesian VSL in 1995 US dollars of only $0.16m.

These values are obviously approximate and somewhat outdated, but nevertheless provide rather haunting food for thought when considering how much should be invested in risk reduction at the societal level across the world.

Whilst the VSL concept can seem alien and cold, the events at Sinabung and the circumstances of the deaths – people had returned to check on their homes and possessions – perhaps suggest that those facing such risky situations may subconsciously perform a VSL-type calculation. For those who stand to lose everything in an eruption, it seems the line between life or livelihood is incredibly blurred.

[1] Miller, TR (2000) Variation between Countries in VSL. Journal of Transport Economics and Policy, Vol 34 No.2

Science Snap (#18): Tragic Sinabung Eruption

James Hickey is a PhD student in the School of Earth Sciences at the University of Bristol. A geophysicist and volcanologist by trade, his PhD project is focussed on attempting to place constraints on volcanic unrest using integrated geodetic modelling.

Last Saturday (1st February 2014) an eruption at Sinabung volcano in Indonesia claimed the lives of 14 people. That death toll has since risen to 16, and could rise further as people battle in hospital with severe burns and other wounds.

A local villager runs from the eruption of Sinabung volcano in Indonesia. Image credit: BBC News.

A local villager runs from the eruption of Sinabung volcano in Indonesia. Image credit: BBC News.

The volcano has been erupting since September 2013 and over 30,000 people have been evacuated from their homes. The Friday before the latest eruption, anxious citizens were allowed back to check on their homes. Many had been sneaking back into the exclusion zone anyway. And herein lies the danger. Despite the obvious inconvenience of being away from home for such a period of time, exclusion zones and evacuations are there for protection and safety. This tragic event is the result of people becoming too complacent around a volcano with a prolonged eruption, and locals not fully understanding the risks associated with such situations.

Hopefully this will serve as a timely reminder, to both locals and scientists. The perennial need for better communication between scientists, locals and civil protection authorities isn’t going away.