Historic Earthquakes

Magnitude 6.9 COSTA RICA
1999 August 20 10:02:21 UTC

Me   6.5                                                             
Broadband Source Parameters:
BROADBAND DEPTH:        19.0 km
BROADBAND FAULT PLANE SOLUTION: 
NP1:Strike=115 Dip=80 Slip= 120
NP2:       222     31        19
Principal Axes:
T              Plg=47  Azm= 56
P                  29      181
RADIATED ENERGY                                                      
No. of sta: 10  Focal mech.  F                                      
Energy       1.4±0.4*10**14 Nm                                      
COMMENT:  A small event is followed about two seconds    
later by a larger event. Depth from synthetics of      
broadband displacement seismograms based on first event.