Last updated on 5 JUN 2021

ANISOtime is a utility package for computing travel times of seismic waves in a laterally homogeneous, transversely isotropic (TI), spherically symmetric medium. This is free software developed by researchers presently or formerly affiliated with the global seismology group of the University of Tokyo. Please verify that you have the Java Runtime Environment (8+) installed before you proceed further. This is required to run ANISOtime.

The User Guide is included in the software, but it also may be viewed here.

For Windows
For macOS
For Linux

Please note that the program automatically updates when a new version is released.

1. Verify that you have the most recent version of Java installed on your machine.
2. Download/Install:
   
   • Windows users: Download the file "anisotime.bat" from the above link and move it to your desktop (or some other folder where you want to use it).
     
   • macOS/Unix/Linux users: Dowload the file "anisotime" from the above link. Open the "Terminal" app, navigate to the place where the downloaded file is stored, and change the user permissions of the file by typing chmod +x anisotime.
3. Launch ANISOtime:
   
   • Windows users: click on the icon. (We are still waiting for our "code signing certificate," so you will get a warning message that the software is unverified. Please don’t worry, and authorize your machine to launch the program. Sorry for this inconvenience.)
     
   • macOS/Unix/Linux users: in the terminal app, type ./anisotime. (We are still waiting for our "code signing certificate," so if you try to launch ANISOtime by directly clicking on the icon rather than through the terminal app, you may get a warning message that the software is unverified. Please don’t worry, and authorize your machine to launch the program. Sorry for this inconvenience.)
4. If you need more information download the User Guide, or read it through the Help tab in ANISOtime after you launch it.

Template input model files for ANISOtime can be found as below:

• Polynomial Structure mode: miasp_aniso.poly
• Named Discontinuity Structure mode: miasp_aniso.nd

Using ANISOtime, compute the traveltimes for the isotropic PREM and anisotropic PREM models (for example, by using Record Section Mode) and discuss the geophysical implications of the following:

1. Triplication phases related to the positive velocity discontinuities at depths of 410 and 660 km.
2. The shadow zone related to the outer core.
3. The difference in the traveltimes between SH and pseudo-SV waves due to the anisotropic structure in the depth range from 24.4 to 220 km.

The source code for ANISOtime can be downloaded here.

Please send email to [email protected] using the subject line “ANISOtime Help” if you have any questions or comments.

Software and documents, Copyright © 2015-2020 Kensuke Konishi, Anselme F.E. Borgeaud, Kenji Kawai and Robert J. Geller