PRELIMINARY FORECAST TEST FOR 2002:


Three Postscript diagrams show prospective test results for NW and SW Pacific
forecasts made for calendar year 2002. The maps are in a format like that of
Figure 8 of Kagan and Jackson (2000; see RECENT PUBLICATIONS below in this WEB
page). Parameters of the 2002 forecasts are the same as used in 2000 and 2001
for both regions. The likelihood test diagram is similar to Figure 9 in the
paper. The earthquakes in the both Pacific regions are consistent with the
forecast results (that is, the catalog falls within the 95% confidence
intervals based on simulations using the model probabilities). 

REFERENCES:

Jackson, D. D., and Y. Y. Kagan, 1999. Testable earthquake forecasts for 1999,
Seism. Res. Lett., 70, 393-403.

Kagan, Yan Y., and David D. Jackson, 2000. Probabilistic forecasting of
earthquakes, (Leon Knopoff's Festschrift), Geophys. J. Int., 143, 438-453.

FIGURE CAPTIONS:

Figure 1a,b.

Color scale tones show the probability of earthquake occurrence calculated
using the Harvard 1977-2001 catalogue; positions of earthquakes in
2002/01/01-2002/12/31 are shown in white. 

(a) Northwest Pacific long-term seismicity forecast: latitude limits from 0.25S
to 60.25N, longitude limits from 109.75E to 170.25E; 34 events from 2002/1/1 to
2002/12/31.

(b) Southwest Pacific long-term seismicity forecast: latitude limits from 0.25N
to 60.25S, longitude limits from 109.75E to 169.75W; 70 events from 2002/1/1 to
2002/12/31.

Figure 2.

Likelihood test of the forecast in previous Figure. We use the 1977-2001
earthquakes as a control set. The solid blue line is the best Gaussian curve,
having the same mean and standard deviation as the simulations. The red curve
corresponds to simulation distributions for the NW-Pacific, while the green
curve is for the SW-Pacific. Curves to the left of the Gaussian curve indicate
that the actual earthquakes were more concentrated in the red zones (high
probability) than predicted by the model, so that the model forecasts over too
broad an area. Curves to the right of the Gaussian curve indicate that the
earthquakes were not as concentrated in the red zones as expected from the
probability model.