Migration of earthquakes with a small stress drop in the Tanzawa Mountains, Japan

Earth, Planets and Space

Table 2 Average values of the stress drop

	Average values of stress drop (MPa)^a
The cluster activity in January, 2012	2.87 [5 eqs.]	8.61 [6 eqs.]
The cluster activity in January, 2012	(1.33–6.20)	(3.52–21.1)
Before and after the cluster activity	13.7 [8 eqs.]	22.8 [10 eqs.]
Before and after the cluster activity	(7.53–25.1)	(14.5–30.0)

^aValues in the left and right columns show stress drops estimated by P and S waves, respectively. Values in brackets indicate the numbers of earthquakes used for calculating the average stress drops (see Table 1). Values in parentheses indicate the ranges for two standard errors