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In this article, we will discuss the difference between epicenter and hypocentre
An earthquake may be defined as the sudden shock of the earth that emits the energy in the earth’s lithosphere causing the formation of seismic waves.
The earthquake can be caused due to volcanic eruption, moving of tectonic plates, formation of the cave in a small area, or due to explosions. It is determined with the help of a seismograph by Seismometers and is measured on the Richter Magnitude Scale.
1. Epicenter
It is the position on the earth’s surface vertically above the place of the hypocentre of an earthquake. This position is expressed by its geographical latitude and longitude.
In major earthquakes, the epicenter is the position where the higher destruction occurs but the length of the subsurface fault fracture may actually be a long one, and destruction can be extended on the surface along the whole fractured zone.
As an example, in the magnitude 7.9 Denali earthquake of 2002 in Alaska, the epicenter was located at the western end of the fracture, but the peak destruction was about 330 km (210 mi) far away at the eastern point. Focal depths of earthquakes taking place in the continental crust majorly vary from 2 to 20 kilometers (1.2 to 12.4 mi).
Continental earthquakes beneath 20 km (12 mi) are rare whereas in the subduction zone earthquakes can begin at depths deeper than 600 km (370 mi).
2. Hypocentre or Focus
It is the center position of the earth from where seismic waves start.
An earthquake’s hypocenter is the point where the strain energy collected in the rock is initially emitted, marking the position where the fault starts to crack. This takes place directly below the epicenter, at a distance known as the focal or hypocentral depth. The focal depth can be determined from measurements depending upon seismic wave phenomena.
As with all wave phenomena in physics, there is uncertainty in such measurements that develops with the wavelength so the focal depth of the source of this long-wavelength (low frequency) waves is hard to calculate accurately.
Very powerful earthquakes emit a large part of their energy in seismic waves with very long wavelengths and therefore a powerful earthquake includes the delivery of energy from a bigger mass of rock.
3. Difference Between Epicenter and Hypocentre
The difference between epicenter and hypocenter is as follows:
| S.No | Epicenter | Hypocenter |
| 1. | It is the position on the earth’s surface vertically above the place of the hypocentre of an earthquake. | It is the center position of the earth from where seismic waves start. |
| 2. | It is observed on or above Earth. | It is observed on the sub-level or underground of Earth. |
| 3. | It produces both body and surface waves. | It produces only body waves. |
| 4. | It records the 2-D (D stands for dimensional) effect on how there is a movement of the waves. | It records the 3-D effect on how there is a movement of the waves. |
| 5. | It is known as Focal Point or Epicentrum. | It is also known as Focus or Ground Zero. |
| Read Also: Construction of an Earthquake Proof Building |
