# Earthworm Modules:
HYPOINVERSE DOCUMENTATION

(last revised Oct 23, 2012)

Complete details of hypoinverse configuration can be found in the official Hypoinverse documentation maintained by Fred Klein at:

- hyp2000-1.3.pdf

Fred's ftp dir: ftp://ehzftp.wr.usgs.gov/klein/

HYPOINVERSE2000 determines earthquake locations and magnitudes from seismic network data like first-arrival P and S arrival times, amplitudes and coda durations. The last version HYPOINVERSE2000 (version 1.2) is in routine use by the Hawaiian Volcano Observatory, The Northern California Seismic Network, the Nevada network, and many other networks. It is the standard location program supplied with the Earthworm seismic acquisition and processing system and has thus gotten wide use. Crustal models can be multiple to cover different regions, and either flat layer or flat layer with linear velocity gradients. Version 1.3 also supports negative magnitudes and crustal models from the HYPOELLIPSE program, including layer models, gradient over halfspace models, depths relative to sea level, negative depths above sea level, deep boreholes, and use of station elevations. It is Y2000 compatible.

### Hypoinverse/Hyp2000_mgr Troubleshooting Tip:

If hyp2000_mgr dies mysteriously when reading its .hyp file, try running the standalone interactive version of hyp2000. This will allow you to see any error messages from hypoinverse, and it allows you to step through a configuation one command at a time.
Just type hyp2000 at a command prompt, and hypoinverse will give the prompt:

    COMMAND?

At this prompt, invoke a complete configuration file by entering @configfile.hyp. Or type a hypoinverse's 3-letter command followed by Enter and hypoinverse will prompt you for all the arguments for that command. Entering each command individually is a great way to find configuration errors!

### Some changes of note for addition of Location Code:

1. The "LET" command now requires five arguments:
   Number of letters in the site code (2-5)
   Number of letters in the net code (0-2)
   Number of letters in the component code (0-3)
   Number of letters in the location code in phase files (0-2)
   Number of letters in the location code in other files (0-2)
   Here's an example of a valid LET command for a .hyp file:

       LET 5 2 3 2 2

### Some changes of note for Hyp2000:

1. Any format containing years is changed. The changes are simple and generally involve expanding years from 2 to 4 digits, and moving other fields to the right. The station file and shadow format had no year field and therefore was not changed. Hypoinverse summary format grows from 154 to 164 columns, hypo71 from 93 to 95, archive format from 100 to 111, and summary shadow did not change length.
2. The exception to 1) is there is no new phase format. The original phase format is still supported, but the century (1900 or 2000) is set as a global parameter for the location run.
3. All magnitudes are now to 2 decimal places in all formats
4. The user selects the 2000 formats with one command. The "200" command has 2 arguments: a) T=use 2000 formats, F=use old formats b) Century to assume for phase format, which has no century field. Thus "cop 5" will still select archive-shadow input, which is useful to those of us who struggle through earthquakes at 3 in the morning.
5. The new archive format has a field specifying a code for the units of amplitude. Presently only the traditional peak-to-peak mm (Develocorder or paper), or 0-to-peak mm (UC Berkeley) are supported. The amplitude field is expanded from F3.0 to F7.2.