Tectonic earthquake
Topic: Interior of the Earth: Earthquakes, Volcanoes and the Layered Earth · NCERT: Class 11, Ch 3 "Interior of the Earth"
Meaning
A tectonic earthquake is caused by rocks suddenly sliding along a fault plane, a break in the crust. Stress builds up while friction keeps the blocks locked. When the stress beats the friction, the blocks slip and release energy as shaking. This is the most common of the five types of earthquakes. Most tectonic quakes happen along plate edges. Some also strike inside stable plates.
Example
The Bhuj earthquake of 26 January 2001 (Mw 7.7) in Kachchh, Gujarat, was a tectonic earthquake. The Latur-Killari earthquake of 30 September 1993 (M 6.2) in Maharashtra was also tectonic, even though it struck in the stable peninsula, far from any plate edge.
Don't confuse with
- Reservoir-induced earthquake: this is set off by water stored in a large reservoir, as at Koyna in Maharashtra (11 December 1967, M about 6.3). A tectonic quake comes from natural stress building up in the crust.
- Volcanic earthquake: this is a special kind of tectonic quake, found only near active volcanoes.