Feeling the earth move!
Thermal Technology and Earthquakes
When we think about earthquakes it is not generally the case that we would consider the United Kingdom as a location for these phenomena to occur. Outside California, most people would think of places such as Alaska, Japan, off the South American coast and the Indian Ocean as earthquake prone areas. But in fact throughout the UK there are between 30-40 earthquakes each year! During the early Spring of 2014 parts of the UK have experienced unpredicted quakes – in February 2014 a quake registering 4.1 magnitude was felt throughout Devon, South Wales and Somerset while in April in Leicestershire two quakes of 3.5 magnitude were felt within 24 hours of each other. An indicator that wherever you are in the world you may be in a risk area for natural disasters.
What is an earthquake?
An earthquake is the trembling of the Earth caused by movement in the plates of the crust of the Earth (the outer layer of the Earth’s surface) where there is a build-up of pressure and a concurrent release of energy. The crust of the earth is made up of a number of tectonic plates – these are constantly in contact with each other and are moved continuously by convention currents from mantle under the crust. When these plates collide or attempt slide past one another there is a build-up of pressure due to the rock pieces catching on each other and the seismic waves cause the ground to shake as the pressure is suddenly released. Quakes can also occur along fault lines which are away from the edges of plates – these are cracks where sections of plate are moving in different directions. Another contributing factor to triggering an earthquake in certain areas of the world can be volcanic activity – eruption of magma from a volcano disturbs the movement of the tectonic plates surrounding the volcano, changing direction and speed of plate transit.
Earthquakes throughout the world vary in severity from very minor through to causing terrible destruction. For example, the devastating Haiti earthquake in 2010 registered 7.1 magnitude killed 222,750 people and affected a total of 3 million** whereas the UK experienced a quake 60 miles off the coast near the Dogger Bank in 1931 with a magnitude of 6.1 which caused minor damage to buildings*. It is thought that in the United Kingdom, the majority of the minor earthquakes felt are due to the fault lines caused by both tectonic plates and as a result of melting ice sheets which once covered much of the country.
Unfortunately there is no single simple way to predict earthquakes. Researchers, scientists and geologists invest ongoing resource into detection of patterns which could predict where and when an earthquake will occur with the intention of being in a position to warn populations in vulnerable areas and strive to prevent as much damage as possible in the event of a quake.
Thermal imaging provides an interesting and innovative approach to predicting earthquakes and faults. First used in 1988 as a method of determining seismic activity, Thermal imaging has since been shown to be highly useful in prediction of the probability of an earthquake through thermal and heat signatures. Certain activity within the Earth’s crust is an indicator that there is movement within the tectonic plates particularly for example, where there is build-up of pressure and energy. This can be seen at the sight of fault lines, between plates and around volcanos. Changes in magma, gas build up and hydrothermal activity can all indicate that there is activity within the Earth’s surface and these changes are detectable as thermal and heat signatures to monitoring equipment. Using forward looking infrared radiometry (FLIR) from hand held devices either on site or airborne, thermography can determine where there is potential for seismic activity. With ongoing monitoring and reliable technology there are opportunities to predict activity in advance of an earthquake occurring. A further adaptation of this technology is the use of infrared cameras on NASA satellites monitoring activity in the crust of the earth on a far larger scale. The IR camera in orbit around the Earth looks for hot spots of surges in the radiation – for example in 1998 Scientists from NASA monitoring the ground temperature at -20c in Zhangbei near the Great Wall of China noted a temperature variation from thermal sensors of 6-9 degrees just prior to a 5.7 magnitude earthquake in the area*** There are, of course, limits to this technology but it certainly represents an exciting and potentially lifesaving method of determining seismic activity.
Amongst natural disasters, earthquakes are one of the most devastating and frightening phenomena that can be experienced. Through changing technology and innovation we are hopefully on a path to determine a way to prevent injury, destruction and death through accurate prediction of where and when earthquakes will occur.
To find out more about innovation in thermal technology visit Thermal Vision Research.
*British Geological Society /** National Geographic / *** NASA / http://onlinelibrary.wiley.com/doi/10.1029/2007GC001910/