Point Source
============

.. _loh1:

SISMOWINE WP2\_LOH1
~~~~~~~~~~~~~~~~~~~

SISMOWINE is intended as a long-term interactive web interface for
verifying numerical modeling methods in seismology. Numerical-method
developers and numerical modelers may compare their solutions with other
solutions. SISMOWINE is a continuation of the original SPICE Code
Validation interface established within the 6th Framework Programme
project.

LOH1 is used as an example here to illustrate the implementation of
source point for earthquake nucleation in SeisSol. The details of the LOH1 model can also be found at 
the `point source example <https://github.com/SeisSol/Examples/blob/master/WP2_LOH1/>`__.

The model uses Right-handed Cartesian, x positive North, y positive
East, z positive downward, all coordinates in meters. The source is
buried at 2000 m in a half-space Earth (Figure [fig:loh1]. The top layer
is 1000 m thick and the bottom layer is 33000 m. The material parameters
are listed in Table [table:loh1].

+--------------+------------+-----------+-----------+-------+-------+
|              | Vp (m/s)   | Vs(m/s)   | density   | Qp    | Qs    |
+==============+============+===========+===========+=======+=======+
| layer        | 4000       | 2000      | 2600      | Inf   | Inf   |
+--------------+------------+-----------+-----------+-------+-------+
| half-space   | 6000       | 3464      | 2700      | Inf   | Inf   |
+--------------+------------+-----------+-----------+-------+-------+

Table: Material properties in LOH1.

.. figure:: LatexFigures/LOH1.jpg
   :alt: Geometry of LOH1 .
   :width: 11.00000cm
   :align: center

   Geometry of LOH1.

Geometry
~~~~~~~~

The mesh is generated using Gmsh.

.. figure:: LatexFigures/loh1_mesh.png
   :alt: Geometry of LOH1 model (Gmsh)
   :width: 11.00000cm
   :align: center

   Geometry of LOH1 model (Gmsh). A 1 km layer of low velocity (Vp=4000
   m/s, vs=2000 m/s) is at the top of high velocity (vp=6000 m/s,
   vs=3464 m/s).

Point source input
~~~~~~~~~~~~~~~~~~

The point source needs to be turned on in *parameter.par* file.
:: 

  &SourceType
  Type = 50
  FileName=’LOH1_source.dat’
  /

The source input file can be generated using the `script <https://github.com/SeisSol/Examples/blob/master/WP2_LOH1/generate_LOH_source_type50.py>`__. Duration of the source is 4
seconds.

Results
~~~~~~~

| The comparison with solution is shown in Figure [fig:compare\_loh1].

.. figure:: LatexFigures/loh1_benchmark.png
   :alt: Benchmark of x-component particle velocity
   :width: 11.00000cm
   :align: center

   Benchmark of x-component particle velocity at receiver point 1 (0.0,
   693.0,0.1). Bule is 4-order SeisSol and orange is SISMOWINE result.