Sunday, 3 April 2011

Is there such a thing as a man-made natural disaster?

Do man-made natural disasters exist? Well I realise that this statement sounds rather contradictory but is it possible that human activity can provoke events that we class as natural disasters, such as a volcanic eruption or an earthquake, for example.

From a discussion I had with Millie, it seems that there is a rather interesting history behind the Lusi volcano in East Java and a lot of controversy surrounding what caused it to erupt and this could possibly be an example of a man-made natural disaster (if such a thing exists). Many geologists blame the unregulated and careless drilling performed by a natural gas company whilst others, the natural gas company included, believe that an earthquake provoked Lusi to start spewing large volumes of mud. Geologist Richard Davies, who was one of the head Geologists at a meeting held in South Africa to determine the cause of the eruption, strongly believes that the evidence suggests that it was the unregulated drilling of Lapindo Brantas. Before I start to try and explain why geologists believe the drilling provoked the eruption, I must point out that I don't study Geology and so I am going to apologise in advance to any Geology students out there who may read this as I am only going to explain the very basics and just hope that I don't get out of my depth - feel free to correct me! Drillers exploring for natural gas bored 1091 metres down through the stratas of sandstone and mudstone and then in an attempt to strength the hole they inserted a steel casing. However, as they continued to drill deeper, they failed to insert more steel casing, thereby weakening the hole. Water and the natural gas they were searching for started to fill the hole and build up pressure which eventually fractured the unprotected rock strata. Hot, pressurised water was then released from the Kujung limestone aquifer. The geothermal energy from the near by arc of volcanoes (the closest one, Arjuno, being 15km away) is believed to explain why the water was so hot. This hot, pressurised water, accompanied by the gas, raced upwards and mixed with the mudstone which resulted in masses of it being liquified. Davies believes that it was the penetration of the already pressurised limestone that caused the entrainment of the liquified mudstone by the hot water which then resulted in it surging through the layers of sandstone and mudstone, until it broke through the surface - and I think we all kind of know what happened next!

Overall, Davies' report concluded that the eruption was triggered by the drilling and the attempt to control a huge influx of water and natural gas that fractured several sections of the borehole. On the other hand, Lapindo Brantas and their senior drilling advisor, who used the same evidence as Davies did for his study, claims that the pressure levels in the well were within the acceptable limits. This is the total opposite to the analysis of the same data that Davies published as he said that the build up of pressure caused the formation of fractures which propagated from the borehole to the surface around 150m away, thus resulting in the eruption. A geologist for the drilling company denies that the levels of pressure in the well would have caused these fractures and instead claims that the erutpion was caused by an earthquake that occured a few days before Lusi starting spewing hot mud. Dr Mazzini claims that the fracture was triggered by an earthquake, of magnitude 6.3, that occured two days earlier and some 280km away. This was contradicted by an independent geologist from Australia, who specialises in geological pressure and rock mechanics, who said that the earthquake "was at least an order of magnitude too small" and that the force felt at the Lusi site would have been "very small and comparable to the effect of a heavy truck passing overhead". Davies also said that although seismic activity can provoke mud volcanoes, both of which are common in East Java, that he was 99% certain that Lapindo's drilling caused the mudflow.

From all of this, I think it is clear to see that the drilling company has a very different view of how the eruption was provoked to that of many of the geologists that investigated the circumstances. However, at the meeting held in South Africa, which was designed to investigate the cause and what was to blame, 42 out of the 74 independent geologists/scientists that attended were convinced that drilling triggered the eruption. In comparision, only three voted that the eruption was triggered by the earthquake. So, what has happened since this Lusi first starting erupting, way back in 2006. Well, initially, Lapindo were ordered, by the Indonesian Government, to pay $400 million worth of compensation to those displaced by this disaster. However, the money was extremely slow at getting to those affected and in September, of that year, the company was sold to Lyte Ltd. for $2! This has effectively released Lapindo Brantas from its responsibilities, both finicial and moral, connected to the disaster that has displaced over 10,000 and left much of the surrounding area inhabitable for possibly decades to come.

So, could this be classed as a man-made natural disaster? Well, the eruption of a mud volcano is classed as a natural disaster and the evidence suggests that the eruption was provoked by human activity, in the form of unregulated drilling. It also seems that it could have been avoided if the drilling company lined the entire length of the borehole with the steel casing, not just the first 1091 metres, as it would have strengthen the hole and, most probably, prevented the formation of fractures in the underlying rock. This is by no means the only example of events, that we associate with being natural disasters, being induced by human activity. Both the Vajont Dam, in Italy, and the Three Gorges Dam, in China, have led to an increase in the frequency and severity of earthquakes and landslides in the surrounding area. In 1963, a landslide occured near the dam, possibly as a direct response to the added pressure placed on the already unstable surrounding area, and not only destroyed the dam but also claimed around 2000 lives. The Three Gorges Dam has not only induced many earthquakes, during and after its construction, due to the immense additional weight that the reservior of water places on the surrounding area but also the raised water level has increased the rate of erosion and thereby the possibilty that landslides will occur. In the first four months of 2010, 97significant landslides were witnessed in the area, that were believed to be linked to the presence of the dam. This is evidence that human activities can have a negative impact on the environment and provoke disasters that can have truly disastrous and lasting impacts on the local people and surrounding area. Is it right to class such events as man-made natural disasters? Well, I think it is a tricky one as they are neither solely man-made disasters or natural disasters but can you have something that is natural yet man-made? One thing is for sure, and inparticular reference to the Indonesian mud volcano, people are not willing to accept that their activities may have induced a natural disaster and that they should take responsibility of the aftermath and so, perhaps, we are not willing to accept that man-made natural disasters actually do exist. Something that did pop into my mind when writing this is that perhaps global environmental change is the, or will be the, best example of a man-made natural disaster. The debate over whether or not it is caused by human activity or is a natural process is likely to be ongoing well into the distant future and perhaps the answer will never be known. However, is this because it is actually a bit of both? Many scientists believe that the earth warms and cools and that the climate changes naturally whilst others argue that the changes we are presently, and are likely to experience, have been induced by humans and our unsustainable lifestyles. Perhaps, in actual fact, the case is that global environmental change is a natural process that has been accelerated and its effects greatened by human activites. This is similar to the situation in East Java as, mud volcanoes are very common, due to the geology of the surrounding area, but, in the case of Lusi, it was provoked by a human activity - and who knows, perhaps Lusi would have erupted in the future, due to natural reasons like an earthquake of a high enough magnitude. I am starting to go slightly off track here and so I had better finish up before I end up going in totally the opposite direction to where I intended to go. So, do you think there is such a thing as a man-made natural disaster and if so, how would you define one and can you think of any examples of one. Or, if you don't think man-made natural disasters exist, what would you class the eruption of the Lusi mud volcano as, taking the view of the majority of geologists, that it was provoked by the unregulated and careless drilling of Lapindo Brantas?

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