[cig-commits] commit: Edits to introduction.

[Mercurial]

changeset:   69:a1b4751101fa
tag:         tip
user:        Brad Aagaard <baagaard at usgs.gov>
date:        Thu Sep 01 14:14:56 2011 -0700
files:       faultRup.tex
description:
Edits to introduction.


diff -r a1f7fff1bb8e -r a1b4751101fa faultRup.tex
--- a/faultRup.tex	Thu Sep 01 13:50:11 2011 -0700
+++ b/faultRup.tex	Thu Sep 01 14:14:56 2011 -0700
@@ -61,7 +61,7 @@ this vast range of scales generally lead
 this vast range of scales generally leads most researchers to focus on
 a narrow space-time window in order to isolate just one or a few
 processes; the limited spatial and temporal coverage of observations
-also justifies this narrow focus.
+also often justifies this narrow focus.
 
 Researchers have recognized for some time, though, that interseismic
 deformation and fault interactions influence earthquake rupture
@@ -110,20 +110,20 @@ deformation, they examined the effects o
 deformation, they examined the effects of low-rigidity layers and a
 fault damaged zone on rupture dynamics. In addition to purely dynamic
 effects, such as amplified slip rates during dynamic rupture, they
-found several effects that would be almost impossible to include
-without resolving both the interseismic deformation and the rapid slip
-during dynamic rupture; the low-rigidity layers reduced the nucleation
-size, amplified slip rates during dynamic rupture, increased the
-recurrent interval, and reduced the amount of aseismic slip
+found several effects that required resolving both the interseismic
+deformation and the rapid slip during dynamic rupture; the
+low-rigidity layers reduced the nucleation size, amplified slip rates
+during dynamic rupture, increased the recurrent interval, and reduced
+the amount of aseismic slip
 
 Collectively, these studies suggest a set of desirable features for
 models of the earthquake cycle in order to capture both the slow
 deformation associated with interseismic behavior and the rapid
 deformation associated with earthquake rupture propagation. These
 features include the general capabilities of modeling elasticity with
-elastic, viscoelastic, and viscoelastoplastic deformation, as well as
+elastic, viscoelastic, and viscoelastoplastic rheologies, as well as
 slip on faults via either prescribed ruptures or spontaneous ruptures
-controlled by a fault constitutive model. Additionally, a model might
+controlled by a fault constitutive model. Additionally, a model could
 also include the coupling of elasticity to fluid and/or heat flow.
 
 Our long-term objective is to develop modeling software with these
@@ -136,23 +136,24 @@ propagation. We plan to seamlessly coupl
 propagation. We plan to seamlessly couple these two types of
 simulations together to resolve the earthquake cycle.
 
-Other compelling reasons led us to develop such a code with the
-capability to model both interseismic deformation and earthquake
-rupture propagation. Both types of simulations require the same basic
+Other compelling reasons led us to develop such a code capable of
+modeling both interseismic deformation and earthquake rupture
+propagation. Both types of simulations require the same basic
 infrastructure: importing of models from mesh generators, parallel
 data structures for finite-elements, bulk constitutive models for
 elasticity, fault implementations for prescribed slip and fault
 constitutive models, and output of the solution and state variables
-over the domain. The two types of simulations tend to use different
+over the domain. The two types of simulations do tend to use different
 boundary conditions, with interseismic deformation usually driven by
 Dirichlet (displacement/velocity) or Neumann (traction) boundary
 conditions and rupture propagation simulations using absorbing
-boundaries to truncate the domains. However, these features constitute
-a small fraction of the code. The primary different between the two
-types of simulations is the time integration scheme, with an implicit
-scheme used in the quasi-static simulations and an explicit scheme
-used in the dynamic simulations; this also results in using different
-solvers as we will discuss later.
+boundaries to truncate the laterl and bottom boundaries of the
+domains. However, these features constitute a small fraction of the
+code. The primary difference between the two types of simulations is
+the time integration scheme, with an implicit scheme used in the
+quasi-static simulations and an explicit scheme used in the dynamic
+simulations; this also results in using different solvers as we will
+discuss later.
 
 Additional motivation for developing PyLith arose from the geophysics
 community as part of the Computational Infrastructure for Geodynamics
@@ -160,20 +161,22 @@ developing robust, open-source code as w
 developing robust, open-source code as well as a forum for gathering
 feature requests from the community. Serving the broad needs of the
 community with limited resources generated further incentives for
-designing PyLith to leverage common infrastructure for simulation
-quasi-static deformation and dynamic deformation. Maintaining two
-seperate code bases would a require considerably greater development
+designing PyLith to leverage common infrastructure for simulating
+quasi-static and dynamic deformation. Maintaining two
+seperate code bases would require a considerably greater development
 effort.
 
-Implementing slip on the potentially nonplanar fault surface
-differentiates these types of problems from many other elasticity
-problems. Complexities arise because earthquakes potentially involve
-offset on multiple, intersecting irregularly shaped fault surfaces in
-the interior of the domain. Furthermore, we want the flexibility to
-either prescribe the slip on the fault or have the fault slip evolve
-according to a fault constitutive model that specifies the friction on
-the fault surface. Here, we describe a robust yet flexible method for
-implementing fault slip, its affect on the overall design of PyLith,
+\brad{Insert transition sentence : modeling fault slip is a key
+  feature} Implementing slip on the potentially nonplanar fault
+surface differentiates these types of problems from many other
+elasticity problems. Complexities arise because earthquakes may
+involve offset on multiple, intersecting irregularly shaped fault
+surfaces in the interior of a modeling domain. Furthermore, we want
+the flexibility to either prescribe the slip on the fault or have the
+fault slip evolve according to a fault constitutive model that
+specifies the friction on the fault surface. Here, we describe a
+robust, yet flexible method for implementing fault slip with a domain
+decomposition approach, its affect on the overall design of PyLith,
 and verification of its implementation using a few benchmarks.
 
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