Physical Geography

Japan Tohoku 2011 Earthquake/Tsunami Case Study

Japan Tsunami Devastation 2011

Japan Tsunami Devastation 2011

This is a brief case study with links and information on the Japan Tohoku Earthquake/Tsunami of 11 March 2011


Japan 2011 Earthquake location

Japan 2011 Earthquake location

The earthquake occurred 140km off the coast of Honshu (the largest of the Japanese islands) in Japan.  The focus (sometimes referred to as a hypocentre)  of the earthquake was 32km.

The USGS recorded the information here.

Click here to see an excellent timed interval of the earthquake and the many aftershocks that occurred following the earthquake.

Japan Sendai 2011 Earthquake Location


Japan Earthquake Clock Time

Japan Earthquake Clock Time

Friday 11 March 1446 local time

The earthquake occurred at 2.46pm which resulted in many lives being lost in the initial earthquake due to many office buildings being full as well as busy roads however a large number of lives were saved as it meant that many people were ready to act when the tsunami warning was heard.  Had it been early in the morning many people would have been at home where the chances of their homes collapsing would have been less but then they would probably have responded slowewr to the tsunami warning.  This however is a point of debate.  Please feel free to comment below.

How strong?

The earthquake was originally described as 8.9 on the Richter scale but then later upgraded to 9.0 making it the 4th largest earthquake ever recorded since 1900.  See the article here.


What were the causes?  This is a complex tectonic area.  Japan is located at the boundary between many tectonic plates.

The Sendai earthquake was caused by the Pacific Plate descending beneath Japan at the Japan trench/subduction zone.


  • 15,845 deaths
  • 5,893 injured
  • 3,380 people missing
  • 125,000 buildings damaged or destroyed
  • Heavy damage to roads and railways and other infrastucture
  • Fires
  • Fujinuma Dam collapse
  • 4.4 million households without electricity
  • 1.5 million without water
  • Fukushima Nuclear Power Plant complex shutdown and meltdown – 20km radius evacuated (US Citizens were told to evacuate by at least 80km)
  • Loss estimates £150 billion (US$235)
  • The tsunami broke icebergs off the Sulzberger Ice Shelf in Antarctica, 13,000 kilometres away
  • Along the Pacific Coast of Mexico and South America, tsunami surges were reported, but in most places caused little or no damage.

What Happened Next?

Japan Three Months After the Tsunami

Japan Three Months After the Tsunami

3 months later these pictures from the Boston Globe showed the progress that was being made in the slow clean up.  The before and after pictures are particularly interesting


How are Lenticular Clouds formed?


Thank you to Mr Caine for pointing out these beautiful Lenticular Cloud pictures on the BBC website here.  They are often mistaken for UFO’s and can be found at low , mid or high levels.

How are they formed? They are formed when moist air flows over raised ground, such as a hill or mountain peak. When the air consists of alternating moister and drier layers of air, it can lead to lenticular clouds  They are also known as pile d’assiettes (French for ‘a stack of plates’).

As a member of the Cloud Appreciation Society I’m always very interested in anything cloud based.  I’m not into Blue Sky Thinking at all..

Hurricane Irene Sunset and weblinks


New York Sunset August 29 2011

This sunset photo following Hurricane Irene in New York City is beautiful.  Taken by Inga Sarda-Sorensen which I found through my Twitter Feed, it underlines the amazing combination of modern communication technology to embrace some truly incredible natural scenes.

Some Hurricane Irene Links:

  • Hurricane Irene has been tracked by Google Maps here 
  • An interesting comparison of Hurricane Irene and Hurricane Katrina here
  • National Hurricane Centre Irene here
  • Hurricane Irene NASA picture here and excellent detailed information here
  • Wikipedia Hurricane Irene here



Iceland Volcano Plumbing

Eyjafjallajokull ash cloud

Eyjafjallajokull ash cloud

A student (thank you Robyn) pointed me in the direction of this excellent article all about the Eyjafjallajokull volcano and its magma plumbing.  It’s a really interesting read particulary how they’re using radimoetric readings from the TerraSAR-X German satellite to look at how the land deformed leading up to the eruption.  This is extremely important in the race to make the science of predicting volcanic eruptions a more accurate one.

Eyjafjallajokull Volcano Plumbing

Eyjafjallajokull Volcano Plumbing

Essentially the eruption was a phreatic one where water mixed with magma to produce the ash materail that caused havoc around Europe for airline travellers. Check out some typically good BBC graphics here on the eruption plume. Check out the brillinat pictures on the eruption on the Boston Globe website here.

5 years since Hurricane Katrina

Hurricane Katrina dogs

Hurricane Katrina dogs

I can’t believe it’s 5 years since Hurricane Katrina.  It was my first year as Head of Geography at Bodmin College and I remember that we’d already had the Boscastle Floods and the Asian Tsunami and later in the year the Kashmir Earthquake.  It was some year for geography case studies.  These brilliant pictures from the Boston Globereally portray the incredible scences during the hurricane event

A tour of impact craters on Google Earth


The largest verified impact crater on Earth, Vredefort Crater in South Africa. Measuring a staggering 250 – 300 km (155 – 186 miles) across, this crater was formed over 2 billion years ago by an asteroid estimated 10 km (6 miles) in size.

Google Sightseeing is a great blog which in its own words states ‘ why bother seeing the world for real’ when you can use Google Earth!  Well I guess it helps reduce the impact to the environment as a consequence of flying to these locations.

Anyway this blog posting has a great range of impact craters to explore

Flood defence in the UK to cost £1billion


Great article from the Guardian here explaining how half a million houses in the UK will be at considerable flood risk.  The cost of defending them will be far less than the cost of dealing with the floods when they occur.  The cost benefit analysis has to be 5 times the cost of the defences.  Apparently the average cost of a burglary6 in the UK is £1000 whereas the average cost to a home following a flood is £20,000 – £30,000!

UK Snow Map


Some incredible scenes across the country as we face Arctic conditions down to -20 degrees.  The map above shows the extent of the snow cover as of 7 January 2010.  It came from the Daily Mail article here.

World Climate Data


Great site here with a range of Climate data and graphs.

There’s also a Google Mash up with pop up climate charts.

Great idea!

Italian Earthquake 6 April 2009


Where?: Medieval city of L’Aquila, 95km (60 miles) from Rome

When?: 0332 6 April 2009

How strong?
: 6.3 magnitude at 0332 local time (lots of people asleep and therefore trapped)  preceded by a 4.6 magnitude quake (no reported damage)

Effects:  Initial reports state that 27 people have been killed, 30 unaccounted for, 3,000 to 10,000 builidngs damaged.  Many historical buildings have collapsed.  As of 1030 6 April 2009.

Why? : Down the middle of Italy is the large Apennine Fault which is orientated NW-SE.  It is a complex geological area and the appenines is largely an accretinary wedge formed due to the process of subduction.  Essentially the region is both a collision zone and a subduction zone between the Eurasian and African plates as well as smaller microplates.  The US Geological Survey has extensive infrmation.

Italian Earthquake Map

Category 1 is the strongest (red)


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