# New Mexico Tech Dept. Earth & Env. Science Ronni Grapenthin - CrusDe Project

## CrusDe - Overview

CrusDe is a plug-in based simulation framework to study effects due to changes in loads resting on the Earth's surface. Such changes could for example involve a melting glacier, oscillating snow loads, or lava flows. The focus in the simulation could be the response of the Earth's crust in terms of stress changes, changes in strain rates, or simply uplift or subsidence and the respective horizontal displacements of the crust (over time). Users are enabled to:

• dynamically select software components that participate in a simulation,
• extend the framework independently with new software components and reuse existing ones, and
• exchange software components and experiment definitions with other users.

CrusDe implements Green's method in which a unit impulse response is convolved with a force as shown in Figure 1. Realizations of its model elements are independent and exchangeable on the basis of a plug-in approach. Experiment definitions are given in XML files (see Listing 1). To this point CrusDe can simulate everything it was given a unit impulse response.

 Figure 1: Data flow (arrows) between {\sc CrusDe}'s software components (boxes). The fundamental equation is given for reference; the terms are vertically aligned with implementing components. The boxes in dark gray with bold arrows mark the minimum of participating software components; elements in light gray are optional. Reflexive arrows denote reuse of components within their category, i.e. a new Green's function can only use other existing Green's functions. Reflexive arrows refer to components that can access functionality of other components of its category. The 2D convolution operator takes data from the Green's and load function. Depending on whether relaxation or load history are defined the 3D convolution must be used, which itself reuses the 2D operator. The result for the examined area is calculated and post-processors can be applied to it. A result handler writes the modeling results in a particular format to the file system or might be used to pass it to a different

\noindent CrusDe's plug-in mechanism aims for straightforward extendability allowing modelers to include, for example, yet not supported Earth models. Current Green's function implementations:

• elastic response, final relaxed response, pure thick plate response (all flat Earth)
can be combined to express:
• exponential decay from elastic to final relaxed response, displacement rates
due to:
• one or multiple disk or irregular loads or a combination of these
that can have independent load history and crustal decay functions.

A complete experiment definition is given in the following:

   Figure 2: A full experiment / model definition for CrusDe given in XML.

I would be pleased to receive new plug-in solutions (sufficiently documented / commented) for any category, discuss the solutions, and make them available to the public.