Earthquakes in Alaska are uncommon as it is not in a seismically active region never the less there were 14 quakes recorded in the last 24 hours ranging between 1.6 and 4.6 magnitude. Alaskan earthquakes have been building up in magnitude and volume since May this year causing some concern that over the next 50 years this could result in an 'extention' to the Pacific Plate. The worrying thing is that these have all been 'near surface' ranging from surface (less than 1 kilometer) to 100 kilometers (62 miles). The largest quake of 2.7 mg was in the Lake Clark area in Southern Alaska whilst a 4.6 mg was recorded yesterday (18th July 2014) in the Noatak region of Northern Alaska and was only at a depth of 10 km. A further (just confirmed) quake of 5.8 mg has been reported near Yakutat with some damage.The Prince William Sound has suffered 3 minor quakes in the last 12 hours The Malaspina Glacier was struck by a 6.0 mg on 17th July 2014. As yet there have been no reported casualties.
Worthy note: the very first recorded seismometre was reportedly 'engineered' by Chang Heng back in 132AD. An ingenious bronze urn decorated with dragons and toads. It could detect earthquakes some 400 miles. The urn was filled with balls and when an earthquake occurred a ball would be dispensed from a dragon's mouth to be collected by the toad. Today seismic activity is registered on the 'Richter Scale' (named after Dr. Charles Richter) who used logarithms to work out the magnitude of a quake. Computers have taken over but with 'reservations' on the accuracy depends upon how near the epicentre they are.Tectonic Plates give scientists an idea of where earthquakes are most likely to occur. Narrow bands which are connected to the Earth's magnetic sphere but regretfully can not tell us when an earthquake will occur. There are 3 main 'plates':
- The Pacific Plate
- The Mediterranean Plate
- The Indian Ocean Plate
Most activity occurs within the boundaries of the Pacific Plate and, also that by which there are active volcanoes.