SAC Software Statistics
Five Years of Distributing the Seismic Analysis Code Software
SAC (Seismic Analysis Code) is a general purpose interactive program designed for the study of sequential signals, especially timeseries data. This article highlights the distribution statistics for SAC software over five years, from 2005-2009.
In 2005, IRIS started distributing the SAC software to IRIS members. In late 2006, IRIS expanded the licensing agreement, allowing the distribution of SAC software to collaborators including the USGS, members of FDSN and other non-U.S. seismological institutes. The new license agreement led to a large increase in the number of SAC requests each year. Between 2006 and 2007, there was a 237% increase in SAC distributions (see chart below).
International demand for the SAC software increased following a new license agreement in 2006. The number of SAC requests started to level off in 2009.
SAC Distribution by Platform
There have been over 3,700 SAC Software requests by scientists and programmers from Feb 2005 to April 2010. The program has gone through several revisions and many scientists request the latest version. SAC is available for Linux, Mac and Solaris computer platforms.
The majority of users request the Linux binary (58%), followed by Mac (29%) and Solaris (13%). The SAC source code is requested by 69% of the users.
SAC distribution by country
Seismologists worldwide use the SAC software distributed by the IRIS DMC. Hover over the interactive map to view the number of SAC distributions by country . Click on a country to zoom in or click on the water to zoom out.
38% of SAC requests come from the USA, while 62% of the requests come from other countries. The total number of SAC requests from China, Japan, Italy and other countries conducting seismic research is displayed in the chart below (2005-2010).
SAC Distributions – International
SAC Distribution by State
SAC has been requested by hundreds of researchers and college students in 42 states. Hover over a state to see the number of SAC distributions. Darker colors represent a higher number of distributions. (Feb 2005 – April 2010).
SAC Distribution – Top Ten States
SAC Requests by Job Title
Requesting SAC Software
A scientist can request the SAC software using the online request form. Once a request is received the information is reviewed by IRIS staff. If information is missing, then a special notice is sent by email asking the user to complete the form. A completed form is typically processed in within one to three days, and if accepted the SAC binaries and installation instructions are sent to the user by email.
Who can request SAC
In addition to IRIS Members and Affiliates, IRIS may also distribute the SAC Software to collaborators such as the U.S. Geological Survey, Air Force Technical Applications Center, members of the International Federation of Digital Seismograph Networks and other non-U.S. seismological institutes (subject to export control) who are involved in relevant research projects with IRIS. The SAC Software is available free through IRIS.
by Tim Knight (IRIS Data Management Center)