A Real

Earthquake.

Seismograms:

TUC = Tucson

PCAZ = Phoenix

GLA = Yuma

WUAZ = Wupatki

A Real

Earthquake.

Seismograms:

TUC = Tucson

PCAZ = Phoenix

GLA = Yuma

WUAZ = Wupatki

Determine distance of earthquake from station GLA at Yuma:

P arrival time46 sec

S arrival time91 sec

(S - P time)45 sec

Distance from station to EQ:distance = (S - P time) X 8 km/sec

= 45 sec X 8 km/sec = 360 km

NOW YOUR TURN T0 DETERMINEDISTANCES FROM OTHER STATIONS!

Determine distance of earthquake from station GLA at Yuma:

P arrival time46 sec

S arrival time91 sec

(S - P time)45 sec

Distance from station to EQ:distance = (S - P time) X 8 km/sec

= 45 sec X 8 km/sec = 360 km

NOW YOUR TURN T0 DETERMINEDISTANCES FROM OTHER STATIONS!

Triangulating on the earthquake:

Draw circle with radius 360 km around GLA.

Use your distances from other seismic stations to “triangulate” the location of the earthquake.

Triangulating on the earthquake:

Draw circle with radius 360 km around GLA.

Use your distances from other seismic stations to “triangulate” the location of the earthquake.

360 km