JiaxuanYou/libcomcat

libcomcat is a project designed to provide a Python equivalent to the ANSS ComCat search API. This includes a Python library that provides various classes and functions wrapping around the ComCat API, and a number of command line programs that use those:

• getproduct Download ComCat product contents (shakemap grids, origin quakeml, etc.)
• getcsv Generate csv or Excel files with basic earthquake information.
• getphases Generate csv or Excel files with phase information.
• findid Find the ID of an event closest to input time/lat/lon parameters.

We recommend using either the Anaconda (https://docs.anaconda.com/anaconda/) or Miniconda (https://conda.io/miniconda.html) Python distributions. These both use the conda packaging tool, which makes installation of dependencies much simpler. To install either of those packages, see the instructions on the web pages for each.

libcomcat uses Python 3.6, so you will need a conda virtual environment with that version of Python installed. To create a conda virtual environment called "libcomcat" with most of the necessary dependencies installed, do this:

conda create -n libcomcat --channel conda-forge python=3.6 numpy obspy pandas xlrd xlwt openpyxl xlsxwriter

Then to "activate" that environment, do:

source activate libcomcat

Then do:

pip install git+git://github.com/usgs/earthquake-impact-utils.git

pip install git+git://github.com/usgs/libcomcat.git

To uninstall:

pip uninstall libcomcat

To update:

pip install -U git+git://github.com/usgs/libcomcat.git

API and command line documentation can be found here:

http://usgs.github.io/libcomcat/

Sample API usage can be found in the notebook:

https://github.com/usgs/libcomcat/blob/master/notebooks/libcomcat_examples.ipynb

If you work in Python, you can use the read_phases() function that comes with libcomcat.

from libcomcat.utils import read_phases event,phases = read_phases('us2000b3dm_phases.csv')

This function reads either CSV or Excel.

If you work in Matlab, we have provided a function, at the top level of this repository, to read the CSV files. To use in your Matlab environment

read_phases Read event and phase data from CSV files created by libcomcat getphases program.

libcomcat is a set of tools available on GitHub for downloading various types of data from the USGS earthquake Comprehensive Catalog, or ComCat. getphases is one of those tools, and is documented here:

http://usgs.github.io/libcomcat/programs/getphases.html

(at command line) getphases . -i us2000b3dm --format=csv
[event,phases] = read_phases('./us2000b3dm_phases.csv') returns an
event structure, which consists of the following fields:
 - id: USGS authoritative ComCat ID.
 - time: Matlab datenum representing origin time.
 - location: String describing location of the earthquake.
 - latitude: Origin latitude.
 - longitude: Origin longitude.
 - depth: Origin depth.
 - magnitude: Event magnitude.
 - magtype: Magnitude type.
 - url: ComCat URL where earthquake information can be found.
 - Any remaining fields will contain moment tensor data, if available.
   These fields will be preceded by moment tensor source and method.
   For example, a moment tensor created by the NEIC using the W-phase
   algorithm will have the following fields:
   - us_Mww_mrr: Mrr moment tensor component.
   - us_Mww_mtt: Mtt moment tensor component.
   - us_Mww_mpp: Mpp moment tensor component.
   - us_Mww_mrt: Mrt moment tensor component.
   - us_Mww_mrp: Mrp moment tensor component.
   - us_Mww_mtp: Mtp moment tensor component.
   - us_Mww_np1_strike: Strike of the first nodal plane.
   - us_Mww_np1_dip: Dip of the first nodal plane.
   - us_Mww_np1_rake: Rake of the first nodal plane.
   - us_Mww_np2_strike: Strike of the second nodal plane.
   - us_Mww_np2_dip: Dip of the second nodal plane.
   - us_Mww_np2_rake: Rake of the second nodal plane.

and a Matlab table object, where rows consist of phase data
and columns are the following:
 - Channel Network.Station.Channel.Location (NSCL) style station description.
   ( '-'  indicates missing information)
 - Distance Distance (kilometers) from epicenter to station.
 - Azimuth Azimuth (degrees) from epicenter to station.
 - Phase Name of the phase (Pn,Pg, etc.)
 - ArrivalTime Pick arrival time (UTC).
 - Status 'manual' or 'automatic'.
 - Residual Arrival time residual.
 - Weight Arrival weight.