Author Archives: Richard Gravelle

New seismic fault found in Idaho, USA

 

 

The well known San Andreas Fault, California, USA

 

By Richard Gravelle

As Haiti continues to suffer following the January 2010 earthquake, and Christchurch, New Zealand is rebuilt, the world has become more and more familiar with the devastation that these events can cause.

It will concern many therefore that scientists in Idaho State University have mapped a new fault in the Rocky Mountains of Idaho that is capable of producing a 7.5 magnitude earthquake, possibly within the next few decades.

Although not the most populated state in the USA (around 1.5 million residents; 0.5% of the population of the US), an earthquake could still cause tremors and aftershocks all the way to the state capital Boise.  The fault extends for 40 miles and is believed to have caused two earthquakes in the past 10,000 years: one occurring 7,000 years ago and the other 4,000 years ago.

John Ebel, professor of geophysics at Boston College, says that uncovering a fault of this magnitude should not necessarily serve as an “alarm that something is imminent”.  However, given the unpredictability of faults, Prof. Ebel suggested that people who live near the fault should familiarize themselves with earthquake procedures and prepare themselves in case an earthquake does occur.

This advice is supported by findings of Crozier et al. (2006) who suggest that the extent to which people’s views on the causes and preventability of earthquake damage can be influenced by their degree of exposure to hazard, as well as what information they have been given about the hazard.

Let’s hope than that people who live in proximity to the fault will be prepared in the event of an earthquake and that major damage and loss of life can be avoided.

BBC News, 18th November 2010. Scientists find new seismic fault in Rocky Mountains

Crozier, M., McClure, J., Vercoe, J., & Wilson, M., 2006. The effects of hazard zone information on judgements about earthquake damage. Area 38 (2), 143-152

Ice melt reveals historical artefacts

By Richard Gravelle

It’s become something of a trend for me to write about the negative effects of climate change, and particularly the retreat of glaciers.  Recently however, I found a news story that does, in some ways, provide a small upshot to climatic warming.

A team of archaeologists working on recently deglaciated land in the Jotunheimen mountains of Norway have revealed that melting ice is exposing historical artefacts faster than they can collect them.  Although the preservation of historical artefacts is not uncommon (Italy’s ice man Otzi for example), Jotunheimen is proving unusual due to the sheer numbers of artefacts being discovered at the same time – around 600 in one area alone.

The items are believed to be pre-Viking hunting equipment, including sharpened sticks, bows and arrows, as well as some items of clothing though to be around 3,400 years old.

Unfortunately, the rate of exposure of such artefacts and the limited time and manpower resources available to the archaeologists means that items are being lost at an alarming rate.  One exposed, items require immediate preservation and refreezing (often within a few days) before they rot away and are lost forever.

With increasing ice mass loss threatening to expose more historical pieces, lets hope that these are found and preserved, and do not become history themselves.

Alister Doyle, Reuters, September 14th 2010, Home of “Ice Giants” thaws, shows pre-Viking hunts.

The future of the Arctic?

By Richard Gravelle

The future of the Arctic in a warming climate is a hotly debated subject.  Retreating sea ice limits and melting ice masses have the potential to change the face of the region as we know it.  Unfortunately however, we may be heading towards a time when the future of the Arctic region is decided in the boardroom, and not by the Earth’s climate.

The commercial consequences of changes to the Arctic were brought to the forefront this week as an international meeting in Moscow sought to deal with the Arctic’s mineral wealth.

It is believed that one quarter of the worlds oil and gas are located beneath the Arctic Ocean, and this has led several countries to lay claim to territory in the area.  A well known example of this took place in 2007 when a Russian submarine planted a flag on the sea floor as a symbolic gesture of Moscow’s intentions.  Since then Norway, Canada, Denmark and the United States have laid claim to the region.  Russia, for example has promised the equivalent of £40 million in pursuing its claim.

The meeting will aim to end territorial disputes and promote cooperation between countries working in the Arctic.  However, with several of the interested countries having submitted, or intending to submit claims to the United Nations, the dispute does not look likely to end soon.

Arctic summit in Moscow hears rival claims – BBC News, 22nd September 2010

Russia plants flag under North Pole – BBC News, 2nd August 2007


Subglacial Lake Drainage Operation Commences

By Richard Gravelle

Engineers have begun an operation to drain a meltwater lake that has formed beneath a glacier in the Mont Blanc massif.

The lake, which lies underneath the Tete-Rousse glacier, threatens to flood the Saint Gervais valley with approximately 65,000 m3 of meltwater.  The valley is home to around 3,000 people, and contains the world-famous ski resort of Chamonix, so the effects of the lake draining could be catastrophic.  A previous flood in 1892 from another subglacial lake killed 175 people.

It is believed that warmer summer temperatures may have caused an increase in meltwater production which caused the lake to form, but that a period of cold temperatures may have closed a number of natural drainage routes, and preventing the water from draining away.

The engineers will have to drill a 40-50 m deep borehole in the glacier ice before they reach the lake water level.   The water can then be pumped away, making the valley safe once more.

It is thought that the drainage operation will cost around €2 (approximately £1,600,000).  However, if the project is successful, then the cost saved in human life and livelihoods will be far greater.

BBC News – France to drain lake under Mont Blanc Glacier, 25th August 2010

Spiegel – Subglacial Lake Threatens Alpine Community, 25th August 2010

Everglades National Park on UNESCO’s ‘Danger List’

By Richard Gravelle

UNESCO’s World Heritage Committee met in Brazil on Thursday (29th July 2010) to discuss the ‘danger list’ of world heritage sites at risk.  The meeting brings good news for the Galapagos Islands, well known for inspiring Darwin’s Origin of Species, which have been removed from the list after significant steps made by Ecuador to protect its ecosystem. 

Sadly however, both the tropical rainforest of Madagascar, and the Everglades National Park of Florida, USA have been added to the list.  Madagascar’s rainforest has suffered at the hands of loggers and illegal poachers in the past year, and development in the Everglades has resulted in a 60% decrease in water flow through the wetlands.

Worryingly for the national park, the addition to the list of the Everglades at the request of the US government isn’t the first time.  The wetlands were previously classified as ‘at-risk’ between 1993 and 2007 due to the effects of Hurricane Andrew.  On this occasion however, the committee cited urban and agricultural development and pollution as the causes for serious degradation of the wetlands aquatic ecosystem.

It is hoped that experts from UNESCO’s World Heritage Centre and the International Union for the Conservation of Nature (IUCN) will visit the property in 2010 to evaluate the state of the park and assist in the development of a conservation plan.  It is hoped that these steps will result in the area being removed from the danger list as soon as possible.

 BBC News – Everglades and Madagascar forests on Unesco danger list. 31st July 2010

 UNESCO – World Heritage Committee inscribes Everglades National Park on List of World Heritage in Danger. 30th July 2010

Ice loss on Mount Everest

By Richard Gravelle

Several weeks ago, I wrote that Nepalese Sherpas have claimed that the effects of climate change are making Mount Everest more dangerous and difficult to climb (Is climate change making Everest more dangerous? June 5, 2010).  It is generally accepted that Everest, like other mountains worldwide, is undergoing increased rates of ice and snow melt.  However, a recent attempt by the Asian Society (AS) to take photographs of Everest from the same spot as George Mallory did in 1921 suggest that the problem may be worse than previously thought.

Comparison of the photographs revels that the main glacier on Everest, the Rongbuk glacier, has undergone a significant loss of ice mass in the last 89 years, a trend which is unfortunately unlikely to be reversed under present conditions.

Photographer David Breashears is quoted as saying “If this isn’t evidence of the glaciers in serious decline, I don’t know what is”.  These photographs act as a stark reminder of the effects of climate change, as well as allowing us to see exactly how environmental changes have occurred over the past century.

BBC News – Comparative photos of Mount Everest ‘confirm ice loss’.  16th Jul 2010

Replanting the Streets

By Richard Gravelle

A recent report by the woodland trust has suggested that trees can play an important role in improving the quality of life in British towns and cities.  Trees have been shown to improve air quality, reduce ambient temperatures and have a positive benefit on people’s health.

It is estimated that 80% of Britons live in urban areas.  However, only 10% have access to woodland within 500 m of their homes.  This is widely attributed not only to urban expansion, but also to reduced planting schemes.  The trust aims to remedy this by planting 20 million native trees every year.  This has been supported by the coalition government, who estimate that each tree planted in central London is worth as much as £78,000 in its benefits to the surrounding area.

The report hopes to influence local planners and promote the growth of a green infrastructure which could save the UK millions of pounds in healthcare costs and improve house prices.

BBC News – Calls to green ‘concrete jungle’.  Mark Kinver, 30th June 2010.

Woodland Trust website