openquake.hmtk.seismicity.declusterer package#

Submodules#

openquake.hmtk.seismicity.declusterer.base module#

Module openquake.hmtk.parsers.catalogue.base defines an abstract base class for CatalogueParser.

class openquake.hmtk.seismicity.declusterer.base.BaseCatalogueDecluster[source]#

Bases: object

Abstract base class for implementation of declustering algorithms

abstract decluster(catalogue, config)[source]#

Implements declustering algorithms

Parameters:

  • catalogue – Catalogue of earthquakes

  • config (Dictionary) – Declustering configuration dictionary

Returns two vectors

openquake.hmtk.seismicity.declusterer.dec_afteran module#

class openquake.hmtk.seismicity.declusterer.dec_afteran.Afteran[source]#

Bases: BaseCatalogueDecluster

This implements the Afteran algorithm as described in this paper: Musson, R. (1999), Probabilistic seismic hazard maps for the North Balkan Region, Annali Di Geofisica, 42(6), 1109 - 1124

decluster(catalogue, config)[source]#

catalogue_matrix, window_opt=TDW_GARDNERKNOPOFF, time_window=60.):

Parameters:

  • catalogue (Instance of the openquake.hmtk.seismicity.catalogue.Catalogue() class) – a catalogue object

  • window_opt (string) – method used in calculating distance and time windows

  • time_window (positive float) – Length (in days) of moving time window

Returns:

vcl vector indicating cluster number, flagvector indicating which earthquakes belong to a cluster

Return type:

numpy.ndarray

openquake.hmtk.seismicity.declusterer.dec_gardner_knopoff module#

Module openquake.hmtk.seismicity.declusterer.dec_gardner_knopoff defines the Gardner and Knopoff declustering algorithm

class openquake.hmtk.seismicity.declusterer.dec_gardner_knopoff.GardnerKnopoffType1[source]#

Bases: BaseCatalogueDecluster

This class implements the Gardner Knopoff algorithm as described in this paper: Gardner, J. K. and Knopoff, L. (1974). Is the sequence of aftershocks in Southern California, with aftershocks removed, poissonian?. Bull. Seism. Soc. Am., 64(5): 1363-1367.

decluster(catalogue, config)[source]#

The configuration of this declustering algorithm requires two objects: - A time-distance window object (key is ‘time_distance_window’) - A value in the interval [0,1] expressing the fraction of the time window used for aftershocks (key is ‘fs_time_prop’)

Parameters:

  • catalogue (Dictionary) – Catalogue of earthquakes

  • config (Dictionary) – Configuration parameters

Returns:

vcl vector indicating cluster number, flagvector indicating which eq events belong to a cluster

Return type:

numpy.ndarray

openquake.hmtk.seismicity.declusterer.distance_time_windows module#

class openquake.hmtk.seismicity.declusterer.distance_time_windows.BaseDistanceTimeWindow[source]#

Bases: object

Defines the space and time windows, within which an event is identified as a cluster.

abstract calc(magnitude, time_cutoff=None)[source]#

Allows to calculate distance and time windows (sw_space, sw_time) see reference: Van Stiphout et al (2011).

Parameters:

  • magnitude (numpy.ndarray) – magnitude

  • time_cutoff (int) – time window cutoff in days (optional)

Returns:

distance and time windows

Return type:

numpy.ndarray

class openquake.hmtk.seismicity.declusterer.distance_time_windows.GardnerKnopoffWindow[source]#

Bases: BaseDistanceTimeWindow

Gardner Knopoff method for calculating distance and time windows

calc(magnitude, time_cutoff=None)[source]#

Allows to calculate distance and time windows (sw_space, sw_time) see reference: Van Stiphout et al (2011).

Parameters:

  • magnitude (numpy.ndarray) – magnitude

  • time_cutoff (int) – time window cutoff in days (optional)

Returns:

distance and time windows

Return type:

numpy.ndarray

class openquake.hmtk.seismicity.declusterer.distance_time_windows.GruenthalWindow[source]#

Bases: BaseDistanceTimeWindow

Gruenthal method for calculating distance and time windows

calc(magnitude, time_cutoff=None)[source]#

Allows to calculate distance and time windows (sw_space, sw_time) see reference: Van Stiphout et al (2011).

Parameters:

  • magnitude (numpy.ndarray) – magnitude

  • time_cutoff (int) – time window cutoff in days (optional)

Returns:

distance and time windows

Return type:

numpy.ndarray

class openquake.hmtk.seismicity.declusterer.distance_time_windows.UhrhammerWindow[source]#

Bases: BaseDistanceTimeWindow

Uhrhammer method for calculating distance and time windows

calc(magnitude, time_cutoff=None)[source]#

Allows to calculate distance and time windows (sw_space, sw_time) see reference: Van Stiphout et al (2011).

Parameters:

  • magnitude (numpy.ndarray) – magnitude

  • time_cutoff (int) – time window cutoff in days (optional)

Returns:

distance and time windows

Return type:

numpy.ndarray

openquake.hmtk.seismicity.declusterer.distance_time_windows.time_window_cutoff(sw_time, time_cutoff)[source]#

Allows for cutting the declustering time window at a specific time, outside of which an event of any magnitude is no longer identified as a cluster

Module contents#