class Arrival(force_resource_id=True, *args, **kwargs)[source]

Bases: obspy.core.event.base.__Arrival

Successful association of a pick with an origin qualifies this pick as an arrival. An arrival thus connects a pick with an origin and provides additional attributes that describe this relationship. Usually qualification of a pick as an arrival for a given origin is a hypothesis, which is based on assumptions about the type of arrival (phase) as well as observed and (on the basis of an earth model) computed arrival times, or the residual, respectively. Additional pick attributes like the horizontal slowness and backazimuth of the observed wave—especially if derived from array data—may further constrain the nature of the arrival.

  • resource_id (ResourceIdentifier) Resource identifier of Arrival.
  • force_resource_id (bool, optional) If set to False, the automatic initialization of resource_id attribute in case it is not specified will be skipped.
  • pick_id (ResourceIdentifier) Refers to the resource_id of a Pick.
  • phase (str) Phase identification. For possible values, please refer to the description of the Phase object.
  • time_correction (float, optional) Time correction value. Usually, a value characteristic for the station at which the pick was detected, sometimes also characteristic for the phase type or the slowness. Unit: s
  • azimuth (float, optional) Azimuth of station as seen from the epicenter. Unit: deg
  • distance (float, optional) Epicentral distance. Unit: deg
  • takeoff_angle (float, optional) Angle of emerging ray at the source, measured against the downward normal direction. Unit: deg
  • takeoff_angle_errors (QuantityError) AttribDict containing error quantities.
  • time_residual (float, optional) Residual between observed and expected arrival time assuming proper phase identification and given the earth_model_ID of the Origin, taking into account the time_correction. Unit: s
  • horizontal_slowness_residual (float, optional) Residual of horizontal slowness and the expected slowness given the current origin (refers to attribute horizontal_slowness of class Pick).
  • backazimuth_residual (float, optional) Residual of backazimuth and the backazimuth computed for the current origin (refers to attribute backazimuth of class Pick).
  • time_weight (float, optional) Weight of the arrival time for computation of the associated Origin. Note that the sum of all weights is not required to be unity.
  • horizontal_slowness_weight (float, optional) Weight of the horizontal slowness for computation of the associated Origin. Note that the sum of all weights is not required to be unity.
  • backazimuth_weight (float, optional) Weight of the backazimuth for computation of the associated Origin. Note that the sum of all weights is not required to be unity.
  • earth_model_id (ResourceIdentifier, optional) Earth model which is used for the association of Arrival to Pick and computation of the residuals.
  • comments (list of Comment, optional) Additional comments.
  • creation_info (CreationInfo, optional) CreationInfo for the Arrival object.


For handling additional information not covered by the QuakeML standard and how to output it to QuakeML see the ObsPy Tutorial.


__abstractmethods__ frozenset() -> empty frozenset object
__doc__ str(object=’‘) -> str
__module__ str(object=’‘) -> str
__slots__ tuple() -> empty tuple
__weakref__ list of weak references to the object (if defined)
defaults dict() -> new empty dictionary
do_not_warn_on list() -> new empty list
item tuple() -> empty tuple
key str(object=’‘) -> str
readonly list() -> new empty list
warn_on_non_default_key bool(x) -> bool

Public Methods

pop If key is not found, d is returned if given, otherwise KeyError is raised.
popitem as a 2-tuple; but raise KeyError if D is empty.

Private Methods


Private methods are mainly for internal/developer use and their API might change without notice.

_pretty_str Return better readable string representation of AttribDict object.

Special Methods

__dir__ default dir() implementation
__eq__ Two instances are considered equal if all attributes and all lists
__format__ default object formatter
__getattr__ Py3k hasattr() expects an AttributeError no KeyError to be
__new__ Create and return a new object.
__reduce__ helper for pickle
__reduce_ex__ helper for pickle
__setattr__ Custom property implementation that works if the class is
__sizeof__ size of object in memory, in bytes
__str__ Fairly extensive in an attempt to cover several use cases.