Data Formats

It is possible to represent seismic event data in different ways. Most of the functions and classes in SeismoStats work with a simple “catalog” format, which lists the events in a table-like structure. For a full description of the Catalog class implementation and its methods, see the Catalog documentation.

Another popular format is QuakeML (xml), which we recommend using for data exchange of event data including important metadata. QuakeML can be easily converted to and form the SeismoStats Catalog format.

Seismostats Implementations

Additionally to the Catalog format, other representations of seismic event data are GRRateGrids, which define seismicity using GR parameters for each grid cell separately, or GriddedMagnitudeBins, which define the rate of magnitudes in each magnitude bin for each grid cell.

Following the convention of QuakeML-RealValues, numerical values can have additional columns with a suffix indicating an uncertainty attribute, for example latitude_uncertainty or longitude_loweruncertainty. The suffix _value indicating the reference/mean value is dropped (latitude instead of latitude_value) for simplicity and will automatically be added when converting to QuakeML.

Catalog

Tabular representation of seismic events. At least a ‘magnitude’ column is required. Additional important columns are time, latitude, longitude and depth. For conversion into other formats some additional columns can be required like magnitude_type or event_type. The Catalog format is used in most of the SeismoStats functions and classes.
Additional columns can be added as required.

longitude	latitude	depth	time	magnitude	magnitude_type	event_type

Additional magnitudes (of different types) can be added as columns following the naming convention latitude_<type>.

For a full definition of the catalog, the following attributes can be defined on the Catalog class:

Attribute	Description
starttime	From when on the catalog is valid.
endtime	Until when the catalog is valid.
bounding_polygon	The area for which the catalog is valid.
depth_min	Minimum depth of the catalog.
depth_max	Maximum depth of the catalog.
a_value	a-value of the catalog.
b_value	b-value of the catalog.
mc	mc of the catalog.
name	Name of the catalog.

ForecastCatalog

An extension of the Catalog format, which allows to define realizations of the same catalog. This is useful for example when generating synthetic catalogs, where each catalog is a different random realization.

The ForecastCatalog has an additional column catalog_id, which is an unique identifier for each realization. Also the attribute n_catalogs is available on the ForecastCatalog class, which defines the total number of realizations of the catalog.

GRRateGrid

Defines seismicity using GR parameters for each grid cell separately.

longitude_min	longitude_max	latitude_min	latitude_max	depth_min	depth_max	rate	a	b	alpha	mc	m_max

For a full definition of the GRRateGrid, the following attributes can be defined on the GRRateGrid class:

Attribute	Description
starttime	From when on the catalog is valid.
endtime	Until when the catalog is valid.
name	Name of the catalog.

ForecastGRRateGrid

An extension of the GRRateGrid format, which allows to define realizations of the same grid. This is useful for example when generating synthetic data, where each realization is a different random realization of the same grid.

The ForecastGRRategrid has an additional column grid_id, which is an unique identifier for each realization. Also the attribute n_grids is available on the ForecastGRRategrid class, which defines the number of realizations of the grid.

GriddedMagnitudeBins

This format has yet to be implemented in SeismoStats.

Defines the rate of magnitudes in each magnitude bin for each grid cell. This way it is possible to define a distribution which does not strictly follow the GR law.

longitude_min	longitude_max	latitude_min	latitude_max	depth_min	depth_max	magnitude_min	magnitude_max	rate

For a full definition of the GriddedMagnitudeBins, the following attributes can be defined on the GriddedMagnitudeBins class:

Attribute	Description
starttime	From when on the catalog is valid.
endtime	Until when the catalog is valid.
name	Name of the catalog.