Thursday, 31 March 2011

Iceland Day 1

Dear All

A few things from the Iceland trip so far! Firstly, it is cold here, not as cold as it was when we dd weather in class, but icy!!

Todays activity was caving, more on that later, looking at the Rift Valley and the Inland Lake, and then one of Icelands most impressive waterfalls, Gullfoss.

So, the Rift Valley first of all, it was a great start to the trip, placing the day in context with the tectonics of the region. The Rift Vally is one f Icealnds main features, and divides the country nearly in two, most major fracture zones run parallel to it, and within it are some of the islands most significant landforms. It is in effect, a smaller version of the East African Rift Valley, a low lying area, very marshy in this case, filled with lakes and volcanoes, and to which many rivers flow towards. On a more cultural note, it is also the location of the worlds earliest, and still active parliament (Þingvellir). It is a particularly pretty spot, and the Parliament (below) is located on the easternmost edge of the North American Plate, and in fact, you can put one foot on either plate in parts of the rift. Where the plates are pulling apart through rifting, a series of normal extensional faults has caused the land in the centre, this photo is taken looking down the junction between the two, the cliff on the left is the American, and the cliff on the right is the European plates:



The Rift is a very pretty area, which we were due to go underneath in our caving adventure, and adventure it was! We went down into an old lava tube, formed from the cooling of the exterior of the lava flows, and where it is insulated in the middle, the lava continues to flow, often collapsing to form the often photographed skylights in Hawaii. Ours was around 7000 years old, but made a tube roughly 5 by 5m througout. The cave was rather icy, and had some spectacular ice formations waiting for us, like these:


Along with the stalacmites of ice, the stalactites where also pretty impressive:


On emerging from the cave, there were a full variety of facial expressions, some obviously thrilled with their caving experiences, some rather relieved to be out of the snow!

See the facebook page after we get back for more photos!

Next up, after a short drive, we were at Geysir National Park. There are some videos of both mud pots and geysirs, but they are particularly difficult to photograph! However, the pools of silica saturated water that were a variety of shades of blue were fantastic, here are two:


The videos and many more pictures will be uploaded into the blog when we return and have a more steady internet connection! Last stop of the day was Gullfoss, a huge fault guided waterfall with two main sections. At low flow (really) this year, the waterfall was impressive, with clear blue waters from its glacial source. Gullfoss is one of the most impressive waterfalls i have ever seen, unfortunately it had got a bit overcast by then, but still well worth a look!




The next post will hopefully be tonight, filled with moss, more waterfalls and some rather wet students, but we have just had a truly fantastic roast lamb dinner with Eva's secret recipe gravy. Yum. 

Monday, 28 March 2011

Holderness Coastline

Dear Lower Sixth!

Welcome to an online post especially for you to help you with your work whilst we are in Iceland. You will be starting your first major case study of this module, the focus is on coastal erosion and management, and the area is Holderness in East Yorkshire. This is one of the most rapidly eroding coastlines in the UK, and can retreat as fast as 2m a year. The stretch of coastline you will be studying runs from Flamborough Head in the North, to Spurn Point i the South, the sediment underlying much of Yorkshire is Glacial till, and there are high grounds to the West which mark the western limit of Ice sheets during the last ice age.

So, what is coastal erosion? Let the Environment Agency explain!
Rock type is important, Till is a very immature rock, it forms under ice sheets and in Yorkshire is as young as 50 000 years old. The rock is soft, unconsolidated and composed of mud's and some sands with pebbles in it:
As such, the rock is very easy to erode, particularly over the winter when wave strength is at its highest, as seen in this short clip of the waves over winter breaking against the soft till:

There are some good intro videos to the case study already made for us, so here's a good basic one:


This is an excellent clip showing a time lapse photo project over a year in Yorkshire showing how much erosion and deposition takes place:


Why is this such a problem for Holderness? Well, you will get plenty from the video notes, including a rather interesting lady who loses her cows over the edge of the cliff. But Holderness is a real tourist honeypot site, there are numerous holiday parks and mobile home sites right on the coast, unfortunately they are at serious risk and many have already been lost to the sea:

There are of course defences in place, but many are now ageing and in need of replacement, such as these groynes at Hornsea which are not overly attractive to tourists wishing to use the beach:
Yet, groynes are a relatively simple form of defence and the tourists would rather have a beach with groynes than none! They do however cause Terminal Groyne Syndrome, a rather painful affliction if you are a beach, which sees the sand piling up in some areas, and therefore being depleted in others (remember sediment cells are systems). The worst example of this is Mappleton, and it has resulted in certain areas of the coastline being protected through an aggressive Hold the line strategy, and some being lost through managed retreat with the creation of the five new bays. 


The decision has been taken to defend Mappleton at the expense of the down drift towns such as Cowden (The former location of the Earle Farm which has now largely fallen into the sea).
This clip is part of the Blue Peter from 1994 that focused on Mrs Earle loosing her farm to the sea, much of this farm has now gone, as a result of the protection installed at Mappleton to protect the road and the village. This is an excellent example of a cost-benefit analysis, it cost less to build two groynes at £1 million each in Mappleton, than to relocate the road and the residents, but the Earle farm paid the price in 1997. To add to their misery, they were then asked to pay for the demolition costs at their farm as the building was slowly falling into the sea. Quite often, insurance companies do not pay for claims as a result of what is known as a "gradually operated cause", as in coastal erosion, so for many of these homes at risk from receding coastlines, there is no compensation.
This is an excerpt from a geography revision forum on the topic:
  • Coastal erosion - Holderness coast, Yorkshire.
    Tip: Remember the shape of the coastline as the man with a beard
    • Main rock is boulder clay so cliffs are unstable. Other main rock is chalk
    • Cliffs retreat by 2m a year
    • 50 villages that exist during the medieval times are lost today
    • 5 km of land already lost
    • Major features (in order from north to south) – Flamborough Head, Holderness Coast and Spurn Head
  • The Great Debate – Protect Mappleton/ B 1242?
    • Problem: Protecting an area of land always mean greater pressure and coastal erosion on neighbouring stretches of coast
Hornsea is a big town so groynes are necessary. However this means greater coastal erosion will occur in the south; meaning it would affect Mappleton. Mappleton is a small village but an important road, the B1242, runs through it and losing it would mean compensation of millions of pounds. Planners decided to protect it, but this would mean the coastal area down further south will suffer from greater erosion (10 metres a year).
FOR Build rock groyne - trap sand at Mappleton - southern coast and farms destroyed
  • One example would be Sue Earl, a farmer in Great Cowden. Although she had lost a lot of land every year, she was determined to keep the farm running. Eventually the sea will claim the whole farm so she had to give up, especially when the farmhouse went too.
AGAINST Do nothing - Mappleton and parts of B 1242 destroyed; huge compensation - sands continue protect southern coast and farms


A new development is that permission has been given for a huge offshore wind farm just offshore from Spurn


Your comparative case study will be Lyme Regis, which we will cover on the trip, but in order to prepare yourself here is a video explaining why Lyme is an important site, not only for the town itself, but also for the South West:


 

Work to do this week:

  1. Watch the video on Holderness and Spurn Head
  2. Read the module booklet pages 48 to 54
  3. Complete the side of the sheet with the map on it.
  4. On the reverse, make bullet point notes on considerations for coastal management split into the four categories (Social, Economic, Political, Environmental) we will add to these when I return.
  5. Answer the past paper questions on pages 55 and 56 for me to take in next Tuesday
 I know we have not yet covered sand dunes and salt marshes, but you need an introduction to management before the field trip to Lyme Regis next week, on that note, please sign up asap, the Thursday and Friday sessions are filling up, and the trip is an important part of your course.

Any questions please have a word with Richard!

Sunday, 27 March 2011

Mass Movement 101

To all Lower sixth geologists and geographers of both years! 

You have recently studied mass movement as part of your course, which is of course the downslope movement of rock and soil under the influence of gravity. Here is an explanation of the key types of mass movement with some videos and after uch request, this post will be bullet pointed for ease of reading, though, personally I feel you need to be reading and making your own bullet points!!

Here is a good intro and a full episode of "When Nature Strikes Back" on Landslides:




Rock Falls
  • dry movements
  • very fast
  • typical on hard rocks
  • more common on rocks that are heavily fractured and jointed as these can be exploited 
  • key weathering process = freeze thaw 
  • Triggers = Earthquakes, heavy rain, eruptions, 
  • Anthropogenic Influences = undercutting, traffic vibrations
This video is an explanation of the hazard at Yosemite National Park, it is very clear on the risks, why Yosemite is prone to falls, and about how to assess impacts and detecting falls:





You may have seen this one in class, but here's how the Norwegians approach mass movement management:






Testing your rock throwing capability:




The Swiss approach - useful for management:




A very technical rockfall management barrier:




Landslides

This is the downslope movement of a large block of material that moves as a coherent mass, ie it retains its internal structure until hitting the base of the slope and fracturing into smaller pieces. It is more common over wet periods, and on steep slopes, and often observed on coastlines. 




  • Relatively dry movements, prompted by water
  • Relatively fast
  • typical on relatively hard rocks, often those that dip towards the base of the slope
  • more common on rocks that are heavily fractured, steeply dipping and easily laden with water
  • key weathering process = water layer weathering, hydration, freeze thaw
  • Triggers = Earthquakes, heavy rain, eruptions, undercutting by the sea
  • Anthropogenic Influences = undercutting, traffic vibrations, building on steep slopes, terminal groyne syndrome, climate change
This fist video is of a region that has been undercut to allow road access, which is clear at the end, and has prompted a massive landslide. It was triggered by heavy rains, but you can clearly see some of the trees remaining upright until the landslide hits the bottom of the slope:



This next video is of a huge landslide that occurred in a malaysian mine, it was predicted but you can clearly see how once it starts, the slope is destabilised and more and more material becomes entrained in the flow:


This Landslide in Italy last year, was spectacularly caught on camera, much of the material remains intact, and it looks like a flowing liquid, but, as with the malaysian video above, there is very little moisture in here, it is nearly a pure gravity driven movement:




Why we shouldn't deforest our rain forests reason number 1003:


Another swiss video, excellent for monitoring and management of landslides! Very informative and some good shots of testing barriers


And here is a barrier being tested:




So, in short, landslides can be managed through structural responses, ie building retaining fences, careful monitoring and avoiding potentially dangerous situations such as undercutting and building on steep slopes.

Slumps

These are very hard to catch on camera, they are similar to a landslide, but the slumped rock remans intact, just resting at a lower angle with the beds and trees tipping back towards the original cliff profile. The largest of the UK's slumps is at Lyme Regis, which you will see on the fieldtrip.


  • Fairly wet, and relatively fast movements
  • Material does not travel far from source
  • typical on soft rocks, often those that are unconsolidated or weakly consolidated
  • most common on muds and clays on the coast
  • key weathering process = hydration
  • Triggers = Earthquakes, heavy rain, eruptions, ash fall, saturation, snow melt
  • Anthropogenic Influences = terminal groyne syndrome, climate change, building on cliff tops.



Here is a photo of a rotational slump from Barton on Sea, note the surface is still vegetated, just at a lower position than  the rest of the cliff:


Unfortunately, i cant find any videos of a slump in progress, if you know if one, post a link below!

Mudflows/Debris Flows

This is a considerably wetter movement than any of the others, here water is the key, in that the excess water equates to extra weight, and the force of gravity acting on the slope causes the rock face to loose all internal structure and to mix with the water to form a dense fluid capable of transporting large boulders. 


  • Very wet movements, prompted by water saturating pore spaces
  • Relatively fast, but speed slows with change in slope and distance from source
  • typical on soft rocks, often those that are unconsolidated
  • most common on muds and clays
  • key weathering process = hydration
  • Triggers = Earthquakes, heavy rain, eruptions, ash fall, saturation, snow melt
  • Anthropogenic Influences = terminal groyne syndrome, climate change building on cliff tops, forest fires
The first video gives a good idea of the movement of a debris flow, this is a flow on the Andes and clearly shows that even at slow speeds, mud flows can move large boulders through traction:


This second video is from California, a region used to debris flows, this one is caused by a forest fire which exposes the soil and with heavy rain and no support, the soil is easily entrained in surface runoff. Note the tractor at the end,  I am not sure if he is meant to be there or not!



This shows an aggressive mud flow in Afghanistan prompted by snow melt, the region is clearly prepared/used to these events as the road is closed off and the gully well eroded:


In terms of management, debris flows can be identified before they start as the conditions that prompt them are fairly well understood. When this happens, barriers can be put in place as the following video explains:


They can be managed structurally, as this video of a barrier under construction shows:


Management

All Mass Movement can be managed through mitigation (lessening the hazard once it occurs) or management (trying to prevent it from happening). As every with geography, the basics for the region are:

  • Education
  • Hazard Mapping
  • Land use Planning
  • Evacuation Procedures
  • Prediction
  • Monitoring
Specifically for mass movement, the biggest enemy is water. Water can be removed through drainage, either surface or below. In places like Lyme Regis, where much of the cliffs are drained, this is done at great cost sub surface in order to preserve the attractions of the area. 

Surface runoff needs to be managed as well as movement through the rock, and no coastal cliff can be controlled without taking into account the coastal as well as terrestrial processes, which is why when considering coastal management, we need to consider coasts as a constantly changing, over different time scales and working as a system, with inputs from both the land and the sea. 

So, not quite bullet pointed all the way through, but a short video summary of different types of mass movement and their management. Post any questions below, remember for AS geography, all physical essays on the coast will need a mention of geology and the risks of different rock types. Mass movement for the A2 is a risk in most tectonically active regions and more of a risk in Developing countries. 

See you all on Monday

Millie


Wednesday, 23 March 2011

Nuclear Energy and Plate Tectonics

As the worlds attention has switched from Japans threefold disaster, perhaps it is time to reflect on the possibility of this disaster happening elsewhere, and to review the effects of the only other nuclear disaster besides the atomic bombs, to have been as threatening.


There have been many articles of late, speculating on the future of the worlds nuclear industry, and in reality, the likelihood of this disaster happening again is low. Nuclear remains one of the safest fuels even including the disaster at Chernobyl. This graphic from new scientist shows the deaths associated with each fuel type per 10 billion KwH of energy:


The impacts of coal, both in terms of extraction and the resultant deaths from poor air quality and pollution, are far greater than Nuclear, a recent study suggests that in the US alone, 13 200 people die every year through inhaling particulates largely produced by burning coal. In total, the UN estimates that 9000 people will have been killed by the chernobyl Meltdown. Pripyat is still evacuated, besides a few illegal re-settlers who returned to the area a few years after the 1986 catastrophe. The surprise fuel source in this graph is hydro, but the anomaly is explained by a year of severe flooding in China that caused a mass failure of dams.

So., does this mean nuclear is the way forwards? Probably not, but we do need to consider that the recent disasters in Japan have been disproportionately represented in the press. The lesson that needs to be drawn here, is that whatever we build, create or try to manage, we wont win against forces of this size. This earthquake knocked the axis of the earth off by 16cm, it moved an entire island 2.5m closer to the states, and created a wave detected thousands of miles away. Luckily, the Tsunami was not as powerful as the 2004 wave, and did not cause extensive damage outside of Japan. 

Also worth considering, is the likelihood of this happening again, as discussed in the New Scientist article distributed in class today, this was a disaster that would have been managed if only one of the disasters had occurred. Japan is no stranger to earthquakes, and widely used nuclear as it has virtually no fossil fuels of its own. So, how many other nuclear power stations are at risk? This fantastic map shows all earthquakes over 4.5 and the location of all reactors. The full map can be viewed here and is interactive:


It is clear that the potential risks are low for the vast majority of reactors, most are not in regions prone to large earthquakes. A blog from the Guardian highlights the risk as being connected to the age of the reactor, and there is some mileage in this. The older the reactor, the more degraded the concrete and casings, and the higher the possibility of the risk. Out of 442 active reactors, 60 were built before 1975, putting them at a higher risk of fault. Possibly of some concern, if we lived in tectonically active region, Hinckley point B1 was built in 1976 and B2 in 1978, in fact our newest power station is Sizewell B, completed in 1995, making it already 16 years old, in an industry where plants were originally predicted to last for forty years.

The map does show some potential threats. Japan is clearly the most active tectonically and with the largest volume of reactors, but there are others in a similar situation. This up close map of the US shows more detail on the links between tectonic activity in the states and reactor locations:





Those most at risk are in California Diablo Canyon and San Onofre, built to withstand a 7.5 and a 7 respectively, however, as little as two weeks ago, a new report highlighted they may not be as quake proof as first thought as a new fault system has been discovered near by. Diablo is built under half a mile from a new fault zone, and Onofre would be susceptible to both quakes and tsunami's both of which are common in California. The next "big one" is overdue and will of course, eventually come, does this mean we shouldn't build nuclear power plants? However, in terms of planning, it is probably not possible to plan for all these hazards, tsunamis hold potential to travel thousands of miles, so you cannot just manage your own coastline, you need to account for all others that could affect you! In terms of the Pacific, thats 21 countries that need to co-operate, manage and monitor not just earthquakes, but landslide risks, volcanoes and asteroids. No easy feat.
It does have to be pointed out, that magnitude 8 and over quakes occur very rarely, see last weeks New Scientist for a theory on linked or coupled mega quakes, and by no means, as far as I am aware, there are no risks of impending nuclear doom and Hinckley is certainly not at risk!

But, for your AS course, you do need to know about Chernobyl as it really represents worst case scenario for Nuclear, and with this type of energy experiencing a world wide renaissance, there has been much coverage and publication of images associated with the Chernobyl meltdown. Here are a few with some explanation:


Taken a few days after the diaster at reactor four, this image shows Chernobyl just before the decision was made to install the sarcophagus (See the Telegraph photo essay for more)



This photo is of a pig born near Chernobyl after the blast, the worst potential effects are to developing foetus' in the womb, and over 60 000 children experience problems associated with the metldown


What about the machinery used in the recovery efforts? It is too irradiated to use, and now sits in a field around 15 miles from the site as you need an NBC suit to go near it:


The problem of Chernobyl is ongoing, the sarcophagus was a hastily put together concrete tomb in 1986, that by 1988 already showed signs of structural stress, original predicted to last for fifty years, it was repaired in 2005, and is due to be replaced by the New Safe Confinement due for construction in 2013. The sarcophagus currently contains The sarcophagus locked in 200 tons of radioactive lava, 30 tons of highly contaminated dust and 16 tons of uranium and plutonium.In 1996 it was deemed impossible to repair the inside of the sarcophagus as radiation levels were estimated to be as high as 10,000 röntgens per hour (normal background radiation in cities is usually around 20-50 microröntgens per hour). The new structure should be more effective and last for 100 years:




Of course what a lot of the press has focused on for the last few days has been the risk of Fukushima releasing radiation into the atmosphere as Chernobyl did, and this radiation moving in the jet streams and coming down over other areas (like wales)



It is important that we do not allow the nuclear threat to overlook the far more significant disaster, the earthquake and tsunami. This image shows the degree of flooding is clearly shown in this before and after photograph of the Sendai region:


Besides the alteration to our axis, and the States-ward movement of Japan, the earthquake was pwoerful enough to shift the Whillans Ice Stream in Antarctica by half a metre, known as a slip event, it poses little risk, and it normally moves around a meter per day.

Here is a fact based round up of the disaster to date:


  • According to the Japanese foreign ministry, 128 countries and 33 international organizations have offered assistance as of Tuesday.
  • Economy Minister Kaoru Yosano told Reuters in an interview last week the total damage to the world's third-largest economy could exceed $250 billion, the equivalent of 2-3 percent of gross domestic product.
  • At least 14,722 buildings have been completely destroyed, the National Police Agency of Japan said on Tuesday.
  • At least 760,000 households in 10 prefectures were without running water as of Tuesday, the Health Ministry said, down from
  • A total of 9,199 people were confirmed dead by Japan's National Police Agency as of 1400 GMT on Tuesday, while 13,786 were reported missing
However, one of the worst damaged roads has already been repaired:



This really represents the difference in levels of development and recovery, Japan's earthquake was over 100 times more powerful than Haiti, yet in Haiti less than 5% of the rubble has been cleared and only 5-10% of the houses needed have been built. The situation is still dire, with much of the population in increasingly unsafe and dangerous refugee camps:


This photo was taken in January of this year, lets hope that it improves soon:


Tuesday, 22 March 2011

Essay from me

Hello

I have written an answer to the timed essay you did in class last week, the next task in your essay skills development, is to use the mark scheme that you will receive with your essay, to mark mine, look for markers in each of the categories, have a read and tell me what you think in class

See you tomorrow!

Weather systems affecting the Cool Temperate Western Maritime Climates represent many benefits and no significant hazards to their populations and industry. Discuss (40)

Cool temperate western maritime climates (CTWM) are found in several countries worldwide, all of which are bordered immediately to their western seaboards by oceans which moderate the climate typical of their latitudes. These countries include Chile, the UK, New Zealand and Western Canada (British Columbia) all of which are classified as MDC's. These countries enjoy climates with a limited range in temperature, significant extremes are rare and the climate is well suited to agriculture and aquaculture. Their populations have made use of these benefits particularly the UK by progressing through their agricultural revolutions, and the demographic transition early in their history. It can be argued that this early development is a product of a temperate climate, however this may be altered by global climate change which poses a significant risk to all these regions. However, this moderated climate is punctuated by extremes in weather conditions, though by definition, the CTWM is changeable on both a short term basis with the passage of anticyclones and depressions, and a significant yearly variation with seasons, when these extremes do occur, their infrequency places both industry and population at risk as these countries are poorly equipped and unused to more climatic events as has been observed in the UK during the 1987 storm, the 2003 heatwave and the two recent severe winter anticyclones.

The CTWM is found across the UK, and is a climate controlled by its location in reference to the tri-cellular model. This country sits beneath the boundary of the Ferrel and polar cells, and as such endures the influence of the jet streams and the Rossby waves created by their undulating path around the northern hemisphere. These high altitude waves direct the path of high and low pressure systems on the surface, predominantly anticyclones and depressions. The degree of sinuosity, either a high zonal flow with few waves, or low zonal flow with a significant north south movement, determines the location of these different pressure systems which bring considerable variations in weather.

The first of these systems, anticyclones, bring different conditions depending on seasons. During the winter months, the descending air brings clear, cloud free skies, very little precipitation and low temperatures. In the UK these temperatures rarely drop below 2 degrees, and during a typical winter anticyclone the hazards for these events are manageable. To the general population the main social hazards are to drivers, black ice and radiation fog are common, particularly during the cold nights, and are the cause of many accidents. They can pose a risk to infrastructure and property with frozen pipes and potholes which are both caused by the expansion of water by 9% as it freezes. The elderly can be at risk from illnesses such as pneumonia, and particularly with rising fuel costs, this risk may be set to increase. In general, these events cause few hazards to industry, and offer the benefit of tourism in Scotland such as ice climbing and associated tourism, the roads are easily managed through gritting and the public is used to these conditions.

There have recently been examples of severe anticyclones over our winters that have brought significant risks. The winter of 2010 saw a significant snow storm followed by a sustained blocking anticyclone that kept temperatures in some regions of the South West as low as -10, and in Scotland a new record of -27 was set. This anticyclone restricted temperatures and allowed the snow and ice to persist to depths of several centimetres. As the country is unused to this, there were numerous impacts on society. There was sustained criticism of the government as we ran out of grit and salt for the roads, the airports were closed for several days creating loss through trade, and the airports were filled with many international students, ranging in age from 10 to 18 for up to four days. This prompted the Chinese government to consider sending a dedicated plane to retrieve children stranded in the UK. The novelty of ice over lakes in the UK caused some people to venture out onto the thin ice which collapsed, killing five, often as a result of attempting to rescue others or animals. The UK does not have a significant number of snow ploughs, our infrastructure is not set up to cope with cold weather, hence many of our major transport lines around the country are closed, including our roads, railways and shipping lanes. This isolates the UK from our international links, and as we are not self sufficient in either food, energy or labour, anticyclones represent a potentially significant impact to our economy.

In the summer months, extreme anticyclones represent significantly different hazards, but also some considerable benefits. During our summer, an anticyclone again brings clear skies, with cool nights, and heat wave type conditions. Daytime temperatures can exceed 30 degrees, which poses the most damaging risk to our population. Intense insolation causes high risk of sunburn and heat stroke, often people do not follow safe guidelines for sitting in the sun and the combination of dehydration and beach weather encourages people to go swimming when they are weakened, which has led to many deaths, particularly during the 2003 heatwave where 23000 people died across Europe. As with winter anticyclones, the demographic most at risk are the elderly, and the very young.
The potential implications from intense heating of the surface are wide spread, and in terms of environmental impacts, could cause widespread damage. Ice caps and glaciers melt at a faster rate in mountainous regions, rivers and lakes that are not glacially fed can dry up, causing widespread drought and hosepipe bans. However, due to the high levels of development, countries can afford to import water, hence comparatively, the disasters could have a more significant impact in regions such as sub-saharan

It can, however, make a positive economic impact. Particularly in the South West if the UK, heat waves bring about a boom in local tourism, especially around honeypot sites such as Lyme Regis and Newquay, creating demand for jobs in the service sector, and helping to encourage re-investment and redevelopment of older coastal engineering schemes, and possibly ensuring that these new schemes are more sustainable and ecologically friendly than more traditional concrete based walls and groynes. Lyme  Regis is an excellent example, showing how natural processes can be developed in the form of the new shingle beach, to dissipate the wave energy, whilst appearing to be very much a natural feature that encourages tourism. Summer Anticyclones also increase the yield of certain crops within the UK, particularly our higher value crops such as English strawberries, and encourages high levels of attendance and associated spending at some of the UK's biggest summer events such as Wimbledon and Glastonbury. The final hazard these systems bring, is to create convectional thunderstorms, the precipitation form which is often channelled directly to surface runoff across the baked ground surface, such as the floods in Boscastle in 2003, where steep topography at the edge of the Dartmoor batholith created significant flash floods and caused over £12 million in damages.

The other significant weather system, a depression, is formed by the slow mixing of two air masses, the tropical maritime and the polar maritime. The differing conditions of the two, combined with the coriolis effect create an anticlockwise rotating system that always moves NE across the country. Where the air masses meet, fronts develop that bring frontal rainfall, and the rising of the warmer air creates low pressure and unstable atmospheric conditions. These systems are normally associated with higher wind speeds, blowing across the pressure gradient and towards the centre of the depression. When these systems are relatively small, they bring our much needed rain, and do so throughout the year, this enables successful agriculture, water supply to populations and industry, and keeps our reservoirs and lakes topped up. They rarely represent hazards, besides sustained precipitation can cause flooding, and deep depressions are rare, and often blown off course towards Iceland, or loose all excess moisture by the time they reach the south east due to the orographic influence of higher ground in the west.

When these systems are very deep, such as during both 1987 and 2008, they are very hazardous. The 1987 storm cost £3 billion in damages by todays estimates, and had a significant impact on our biodiversity and ecosystems. This storm had a low pressure centre of 963 millibars, and winds speeds approaching hurricane strength. Many lightweight coastal tourist centres such as caravan parks and chalets suffered almost total devastation, and over 15 million of the UK's trees were lost in one night. In addition to several fatalities, there was extensive damage to property and infrastructure, and again transport routes and trade were affected. It is rare for a storm to persist for so long overland, but this event affected nearly the entire country, and with restricted emergency services, recovery was slower than many would have liked. In 2008, another severe depression occurred in March, just before the start of the tourist season, damaging coastal regions, including some defences which a an impact on tourism that year.
These events raise the question of funding for new coastal defence projects, as with rising sea temperatures and a predicted increase in extreme weather, our coastal towns are both the UK's biggest tourist resource, and the most vulnerable areas of the country. Low pressure systems also pose the risk of a significant storm surge which when combined with high tides raises the risk of overcoming coastal defences.

These events must be placed in context, by comparing them to other climate regions and associated hazards. Our level of development ensures we are able to recover faster from any hazard than a developing country, and all of our most hazardous weather systems are short-lived. The benefits of our climate certainly outweighed the hazards early on our development, as they ensured we could feed our populations and not suffer water stress which would have limited our ability to develop. In comparison to a failed monsoon in India, or another category four or five hurricane in Louisiana, these impacts are certainly manageable, and with the advent of better weather forecasting and prediction, the hazard can be mitigated. However, this situation may change over time as the predicted patterns of global warming play out. As a country we are kept warmer than we should by our proximity to the ocean, and the influence of the gulf stream. Should a large volume of freshwater enter the North Atlantic, and the Gulf Stream shut down (or the North Atlantic Deep Water), we would loose this influence, and be subjected to an icy and far colder yearly temperature which would restrict future growth. Should the number of extreme events per year increase, our older defences will be overwhelmed, we have cut our spending on these as a country, and we will have to adapt to a new climate, which could bring benefits, but will enhance the risk posed by the CTWM.

Overall, the threats to population and industry are rare, and uncommon, but significant when they occur. The benefits of the CTWM are felt year round, and have brought all these regions economic and social prosperity. The threat posed by global climate change is one that can be addressed through research and development into predicted changes and patterns, and given enough time, which may be the issue, developed countries may well be able to managed sufficiently under their new conditions. The two main weather systems are therefore both important, when extreme both are potentially damaging, but represent a manageable risk.

Monday, 21 March 2011

New Library Stock

Dear Geographers,

There are now some new additions to the Library which you may well like to check out. By request, the fantastic series "How Earth Made Us" is now in stock, it is a wonderful series for A-Level as it covers in great detail and with some fantastic graphics the earth and our relation to it, covering tectonics, rivers, winds and finally how we are now altering the planet as a result of our development and industrialisation.

This is most suited to the A2 groups who have now done tectonics and population and should be drawing the links between different areas of the syllabus. It is however and excellent geography show and will be a useful revision resource to everyone. In addition, Human Planet is now is as well and is another great way of exploring the links between our planet and the way in which we live.

You can find all the mentioned resources in the library, you may need to reserve some of our more popular titles, but there is a special geography display:



Not only movies, but also these old fashioned square-ish things called books that you read and learn from! Very strange concept to read for pleasure, but we do have both of the Al Gore books on climate change along with some interesting textbooks and novels.

In terms of movies, not one to check out for a relaxing evening in, but Darfur is the movie of the week, I have to warn you, I was hiding behind the sofa for a lot of this one, it is horribly graphic, but if you dont know about the Darfur crisis, take a look. It does not hold back on the gruesome details of the genocide that is currently taking place here. The movie is disturbing, but represents the horrors that rarely make it into our press.

You have been warned, it is a 15, but it is borderline to my eyes.

Check out the trailer here:


On a lighter note, WallE is in, recycling in a future world, and the revision questions to go with Dantes Peak will be on the display tomorrow - test your volcanology!