(redirected from hypocentral)
Also found in: Dictionary.


The point along a fault where an earthquake is initiated.



the focal point of an earthquake. The depth at which a hypocenter lies can vary from 0 to 700 km. The source of underground shock is movements along tectonic faults, which vary in length up to hundreds of kilometers. In this sense, the hypocenter means the point from which the fault began to rip open. In the upper parts of the earth’s crust (up to 20 km) the hypocenter occurs as a result of brittle deformations in a rock series. Deeper hypocenters arise where plastic deformations prevail.

References in periodicals archive ?
Previous determinations of hypocentral parameters ignore historical data from previous seismic events and instead use only information recorded during current earthquakes.
Where r is a vector of travel time residuals with dimension L (= MA-N) dh is a vector of hypocentral parameters adjustment with dimension 4N and dU is a vector of slowness parameter adjustments having dimension P and B denote an LA-4N matrix related to the derivatives of travel times with respect to hypocentral parameters.
The hypocentral location of the AE multiplets in the Basel data set identified at low and high frequencies is determined by double difference (DD), one of the high-resolution relative mapping techniques [7].
Este metodo se basa en la consideracion de que la distancia hypocentral entre dos sismos localizados en una misma estacion es pequena comparada con la distancia eventos sismico - estacion y la heterogeneidad de la velocidad; entonces el camino del rayo entre la fuente simica y una estacion comun es similar a lo largo del rayo.
Both events had hypocentral depths of approximately three miles, similar magnitudes (a duration magnitude 2.
Based on these coordinates and coordinates of underground seismic stations one can calculate the hypocentral distance between the focus and the respective site of observation.
Effect of inaccurate assumption Vp velocity of 200 m/s deviation of average value Vp = 3800 m/s, could cause at hypocentral distance of 1000 m the error of 53 m.
Hypocentral locations of the aftershocks were determined with the help of computer code HYPO71PC (Lee, 1990) using body wave data recorded by local seismic network.
Aftershock characteristics give clues regarding the nature of the relatively long-term processes redistributing stress following instantaneous stress changes associated with a mainshock (Wesson, 1987) It seems likely that this was responsible for the concentration of stress in the hypocentral region of the largest 1993 aftershocks prior to and resulting in the nucleation of the 1995 mainshock Such systematic northward migration led to suggesting an initial model for earthquake migration in the Gulf of Aqaba (Figure 6), although real migration would likely have been more complicated However, the largest aftershock's epicentre in this model represented the stresses nucleation area and location of the next large mainshock (Figure 6)