Source code for openquake.hmtk.sources.simple_fault_source

# -*- coding: utf-8 -*-
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# Copyright (C) 2010-2023 GEM Foundation, G. Weatherill, M. Pagani,
# D. Monelli.
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# The Hazard Modeller's Toolkit is free software: you can redistribute
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# Earthquake Model).
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# hope that it will be useful to the scientific, engineering, disaster
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"""
Defines the :class openquake.hmtk.sources.simple_fault_source.mtkSimpleFaultSource, which
represents the openquake.hmtk defition of a simple fault source. This extends the :class:
nrml.models.SimpleFaultSource
"""
import warnings
import numpy as np
from math import fabs
from openquake.hazardlib.geo.point import Point
from openquake.hazardlib.geo.line import Line
from openquake.hazardlib.geo.surface.simple_fault import SimpleFaultSurface
from openquake.hazardlib.source.simple_fault import SimpleFaultSource
import openquake.hmtk.sources.source_conversion_utils as conv


[docs]class mtkSimpleFaultSource(object):
    """
    New class to describe the mtk Simple fault source object

    :param str identifier:
        ID code for the source
    :param str name:
        Source name
    :param str trt:
        Tectonic region type
    :param geometry:
        Instance of :class:
        openquake.hazardlib.geo.surface.simple_fault.SimpleFaultSource
    :param float dip:
        Dip of the fault surface
    :param float upper_depth:
        Upper seismogenic depth (km)
    :param float lower_depth:
        Lower seismogenic depth (km)
    :param str mag_scale_rel:
        Magnitude scaling relationsip
    :param float rupt_aspect_ratio:
        Rupture aspect ratio
    :param mfd:
        Magnitude frequency distribution as instance of
        :class: openquake.hazardlib.mfd.base.BaseMFD
    :param  float rake:
        Rake of fault
    :param catalogue:
        Earthquake catalogue associated to source as instance of
        openquake.hmtk.seismicity.catalogue.Catalogue object
    """

    def __init__(
        self,
        identifier,
        name,
        trt=None,
        geometry=None,
        dip=None,
        upper_depth=None,
        lower_depth=None,
        mag_scale_rel=None,
        rupt_aspect_ratio=None,
        mfd=None,
        rake=None,
    ):
        """
        Instantiate class with just the basic attributes identifier and name
        """
        self.typology = "SimpleFault"
        self.id = identifier
        self.name = name
        self.trt = trt
        self.geometry = geometry
        self.fault_trace = None
        self.upper_depth = upper_depth
        self.lower_depth = lower_depth
        self.mag_scale_rel = mag_scale_rel
        self.rupt_aspect_ratio = rupt_aspect_ratio
        self.mfd = mfd
        self.rake = rake
        # Check that input dip is between 0 and 90 degrees
        if dip:
            assert (dip > 0.0) and (dip <= 90.0)
        self.dip = dip
        self.catalogue = None

    def _check_seismogenic_depths(self, upper_depth, lower_depth):
        """
        Checks the seismic depths for physical consistency
        :param float upper_depth:
            Upper seismogenic depth (km)

        :param float lower_depth:
            Lower seismogenic depth (km)
        """
        # Simple check on depths
        if upper_depth:
            if upper_depth < 0.0:
                raise ValueError(
                    "Upper seismogenic depth must be greater than"
                    " or equal to 0.0!"
                )
            else:
                self.upper_depth = upper_depth
        else:
            self.upper_depth = 0.0

        if not lower_depth:
            raise ValueError(
                "Lower seismogenic depth must be defined for "
                "simple fault source!"
            )
        if lower_depth < self.upper_depth:
            raise ValueError(
                "Lower seismogenic depth must take a greater"
                " value than upper seismogenic depth"
            )

        self.lower_depth = lower_depth

[docs]    def create_geometry(
        self, input_geometry, dip, upper_depth, lower_depth, mesh_spacing=1.0
    ):
        """
        If geometry is defined as a numpy array then create instance of
        nhlib.geo.line.Line class, otherwise if already instance of class
        accept class

        :param input_geometry:
            Trace (line) of the fault source as either
            i) instance of nhlib.geo.line.Line class
            ii) numpy.ndarray [Longitude, Latitude]

        :param float dip:
            Dip of fault surface (in degrees)

        :param float upper_depth:
            Upper seismogenic depth (km)

        :param float lower_depth:
            Lower seismogenic depth (km)

        :param float mesh_spacing:
            Spacing of the fault mesh (km) {default = 1.0}
        """
        assert (dip > 0.0) and (dip <= 90.0)
        self.dip = dip
        self._check_seismogenic_depths(upper_depth, lower_depth)

        if not isinstance(input_geometry, Line):
            if not isinstance(input_geometry, np.ndarray):
                raise ValueError(
                    "Unrecognised or unsupported geometry " "definition"
                )
            else:
                self.fault_trace = Line(
                    [Point(row[0], row[1]) for row in input_geometry]
                )
        else:
            self.fault_trace = input_geometry
        # Build fault surface
        self.geometry = SimpleFaultSurface.from_fault_data(
            self.fault_trace,
            self.upper_depth,
            self.lower_depth,
            self.dip,
            mesh_spacing,
        )

[docs]    def select_catalogue(
        self,
        selector,
        distance,
        distance_metric="joyner-boore",
        upper_eq_depth=None,
        lower_eq_depth=None,
    ):
        """
        Selects earthquakes within a distance of the fault

        :param selector:
            Populated instance of :class:
            `openquake.hmtk.seismicity.selector.CatalogueSelector`

        :param distance:
            Distance from point (km) for selection

        :param str distance_metric
            Choice of fault source distance metric 'joyner-boore' or 'rupture'

        :param float upper_eq_depth:
            Upper hypocentral depth of hypocentres to be selected

        :param float lower_eq_depth:
            Lower hypocentral depth of hypocentres to be selected

        """
        if selector.catalogue.get_number_events() < 1:
            raise ValueError("No events found in catalogue!")

        # rupture metric is selected and dip != 90 or 'rupture'
        if ("rupture" in distance_metric) and (fabs(self.dip - 90) > 1e-5):
            # Use rupture distance
            self.catalogue = selector.within_rupture_distance(
                self.geometry,
                distance,
                upper_depth=upper_eq_depth,
                lower_depth=lower_eq_depth,
            )
        else:
            # Use Joyner-Boore distance
            self.catalogue = selector.within_joyner_boore_distance(
                self.geometry,
                distance,
                upper_depth=upper_eq_depth,
                lower_depth=lower_eq_depth,
            )

        if self.catalogue.get_number_events() < 5:
            # Throw a warning regarding the small number of earthquakes in
            # the source!
            warnings.warn(
                "Source %s (%s) has fewer than 5 events" % (self.id, self.name)
            )

[docs]    def create_oqhazardlib_source(self, tom, mesh_spacing, use_defaults=False):
        """
        Returns an instance of the :class:
        `openquake.hazardlib.source.simple_fault.SimpleFaultSource`

        :param tom:
             Temporal occurrance model
        :param float mesh_spacing:
             Mesh spacing
        """
        if not self.mfd:
            raise ValueError("Cannot write to hazardlib without MFD")
        return SimpleFaultSource(
            self.id,
            self.name,
            self.trt,
            self.mfd,
            mesh_spacing,
            conv.mag_scale_rel_to_hazardlib(self.mag_scale_rel, use_defaults),
            conv.render_aspect_ratio(self.rupt_aspect_ratio, use_defaults),
            tom,
            self.upper_depth,
            self.lower_depth,
            self.fault_trace,
            self.dip,
            self.rake,
        )