MELTS applets

NOTE: The CORBA MELTS applet is a newer MELTS/pMELTS applet that uses a superior client/server communication protocol and an enhanced graphical user interface.

System requirements

A browser with the following:

The browser may prompt you to grant certain privileges to the applet in order to access local files or to print. Denying those privileges does not disable other functionality.

Run the applets

Java 1.2 MELTS Choice Applet

After you click one of the buttons, the applet appears in its own window.

Note: If nothing appears in the new window (i.e., it remains a blank gray screen), then either the server is down or your browser is behind a firewall. If the three-button graphic does not appear above, your browser is not Java 1.2-compatible or has Java disabled.

Help for MELTS, pMELTS and calcMELTS applets

About the applets

A server (, maintained by Mark Ghiorso and located at OFM Research Inc. - West, provides the computational engine for three Java applets that implement MELTS, pMELTS and the mineral property database (Calc).

The Calc applet provides thermodynamic properties of mineral endmembers and solid solutions known to the MELTS package. The user must input mineral composition, temperature and pressure. The MELTS and pMELTS applets provide a means to calculate heterogeneous phase equilibria in magmatic systems as a function of bulk composition, temperature and pressure.

The MELTS applet is based upon the work of Ghiorso and Sack (1995) and Asimow and Ghiorso (1998). pMELTS is a revised calibration optimized for mantle compositions and pressures and is based upon the work of Ghiorso, Hirschmann, Reiners and Kress (2002).

Computations requested through the applet interface are transmitted to the OFM server and interpreted by a Java/C program that performs the requested calculation, gathers the results and transmits them back to the applet. Because communication between the applet and the server requires an open channel - the identity of client and server are known to each other - these applets do not work if the client (i.e., the browser) is behind a firewall or some Internet switch that hides the identity of the client from the net. Please note that applet performance depends on the quality of your Internet connection and the resources available to the browser/viewer running on your client machine.