How to use the Make Map options
(view map example)

Scale map to data
Choosing this option means that the map created will only include the geographic region in which the data is contained (plus a few degrees).

Map region
You can set an exact region to map using latitude and longitude. If the map is scaled to the data, the parameters of the map will appear in this section after the first map is made.

Large View
A larger scaled map than the default. The difference between the default size and "larger" size is dependent on the size of the area being mapped.

Plates
We have downloaded plate boundary information from the Geological Survey of Japan site (No URL available at this time).

Cities
The city database is from a site done by the United Nations Statistics Division. The city database is for geographical reference (population data may not be current).

Map title
You can create your own map title. You may leave this option blank.

Zoom
The positive numbers zoom in, negative zoom out. The zoom function "sticks" with each use so be sure to set zoom to "None" if you wish to redraw the map without changing the perspective.

Recenter
Clicking on the map will redraw the map with your click point as the new center. The new map will include any new options you have chosen. If you have selected a zoom factor, the zoom will center in (or out) on your click. If you wish to redraw the map without recentering, click the Make Map button instead of the map.

Advanced Options for Event Maps

The advanced options are just that - optional. You do not have to change any of the default settings to make a map. We have provided these options because we realize that some users may want to map more than one region for comparative study or to have control over the size of the symbols used. (One benefit of controlling the "bin" options is that maps of different scales can display event points at the same scale. )

Top data bin
The bin (or grouping) that contains the largest magnitude events. Example: If you search for all events between magnitude 5.0 and 6.0, the top bin would be the one holding the 6.0s. The number of different magnitudes in the top bin is determined by the bin width and/or number of bins.

Maximum symbol size
The largest symbol size used to display events in the top data bin. (If only one bin is selected then this symbol size will be used to represent all events.)

Bin width
The magnitude difference by which data is put into different bins. Example: Defining a bin width of 1 will cause events with magnitudes which differ by more than 1 to be in different bins (i.e. represented by different symbol sizes).

Because you are limited to 5 bins (see below), choosing a bin width that separates magnitudes into more than 5 bins will result in the lowest bin holding all the "left over" magnitudes. Example: A query resulted in a list of events ranging in magnitude from 3.0 to 8.0. We set the bin width to be 1 and number of bins to 4. The bins would fill like this: <6 , 6-6.9 , 7-7.9 , >=8

Number of bins
How many symbols you want to use to display events of different magnitudes. Example: If you searched for all magnitude 5.0 to 6.0 events and you wanted to display these using only 3 bins, you might set the bin width to be 0.5. The three bins would contain events like so: bin 1] < 5.5 , bin 2] 5.5-5.9 , bin 3] >= 6. If you want to draw attention to depth instead of magnitude, you might consider picking only one bin (i.e. one symbol size) for all events regardless of magnitude.

If these explanations are not helpful, please send e-mail to w for more help.