Waveform View Introduction

First, users should read the Step 2: Modify picks and amplitudes on event waveform channels (Waveform View) section for an introduction to the Waveform View with an event loaded into Jiggle. The Waveform View screenshot from this section, with a loaded event, is reproduced below.

Figure

If an event is not loaded into Jiggle, the Waveform View is empty (screenshot below).

Figure

TODO Section

Load waveforms for a single event ā€“ time series

"Selected Solution" with event ID snapshot

Sort by distance to each station / channel

For the SCSN, Waveforms are not only from the CI network, but are also imported from neighboring networks such as AZ, NC, NN.

"Model..." menu

"Event..." menu

Waveform Data Source

The event waveforms need to be read into Jiggle from a database, before displaying them and picking phases/amps/codas in Waveform View. Different settings need to be applied in Jiggle, depending on the following conditions:

  • Is the origin event type (ETYPE in Catalog View) an earthquake or trigger?
  • If the event is an earthquake, do we want to read in and display triggered waveforms or continuous waveforms in Waveform View?

Waveform Data Source: Trigger

If ETYPE is "trigger", then it is necessary to select from the top menu bar: "ModelWaveform source/model...WS Trigger" (screenshot below) in order to view the waveforms. Notice that in the Status Bar in the bottom right corner, the first box says "Trigger" and the second box says "pwsgibbes" which is the source of the continuous waveforms that are displayed.

Figure

If the settings are different from the ones that are currently set, the dialog boxes below will appear before the waveforms are displayed. First, Jiggle should reload all data for the selected event from database tables (left). Second, the event should be reloaded into Jiggle (right). Click "YES" to proceed in both boxes.

An alternate, more time-consuming, way to selecting "ModelWaveform source/model...WS Trigger" to display "trigger" events is to edit the Jiggle properties. From the top menu bar, select "PropertiesLoad properties...".

First go to the "TimeWindow Model" tab, select "Trigger" for the "Model Name:" from the drop-down menu, and click the "Set" button (screenshot below): Figure

Next click the "Wave DataSource" tab, and select the "WaveServer" button under the "Waveforms Read From" section, with the source of continuous waveforms set as "pwsgibbes" (screenshot below). These settings apply to the SCSN; other RSNs would need to click the "Edit WaveServers" button to modify their database settings, including the group name, server name, and port, and test their database connection. Figure

The dialog box with the following message may appear, go ahead and click "OK".

If the settings are different from the ones that are currently set, the dialog boxes below will appear before the waveforms are displayed. Click "YES" to proceed in both boxes.

Waveform Data Source: Earthquake with Continuous Waveforms

If ETYPE is "earthquake", the user has an option to read in either continuous or triggered waveforms from the database. (Recall from the previous section that only continuous waveforms can be used to display "trigger" event types in Jiggle.)

This section explains how to read continuous waveforms from the database near the time of the earthquake, although this is not standard practice in the SCSN.

The easiest way is to select from the top menu bar: "ModelWaveform source/model...WS Power Law" (screenshot below) in order to view the waveforms (for an example event with ID 38422815). Notice that in the Status Bar in the bottom right corner, the first box says "Power Law" and the second box says "pwsgibbes" which is the source of the continuous waveforms that are displayed. There are a total of 3743 channels from 659 stations, although some channels (such as NP.5232.HNZ, PB.B081.HNZ, PB.B081.HN1, PB.B081.HN2) do not have any waveform data available.

Figure

If the settings are different from the ones that are currently set, the dialog boxes below will appear before the waveforms are displayed. First, Jiggle should reload all data for the selected event from database tables (left). Second, the event should be reloaded into Jiggle (right). Click "YES" to proceed in both boxes.

An alternate, more time-consuming, way to selecting "ModelWaveform source/model...WS Power Law" to display "earthquake" events with continuous waveforms is to edit the Jiggle properties. From the top menu bar, select "PropertiesLoad properties...".

First go to the "TimeWindow Model" tab, select "PowerLaw" for the "Model Name:" from the drop-down menu, and click the "Set" button (screenshot below): Figure

Next click the "Wave DataSource" tab, and select the "WaveServer" button under the "Waveforms Read From" section, with the source of continuous waveforms set as "pwsgibbes" (screenshot below). These settings apply to the SCSN; other RSNs would need to click the "Edit WaveServers" button to modify their database settings, including the group name, server name, and port, and test their database connection. Figure

The dialog box with the following message may appear, go ahead and click "OK".

If the settings are different from the ones that are currently set, the dialog boxes below will appear before the waveforms are displayed. Click "YES" to proceed in both boxes.

Waveform Data Source: Earthquake with Triggered Waveforms

If ETYPE is "earthquake", the user has an option to read in either continuous or triggered waveforms from the database.

This section explains how to read triggered waveforms from the database for this earthquake. Some seismic stations only record waveforms when they are triggered by an earthquake signal above the threshold; these stations do not record continuous waveform data.

For "earthquake" events, SCSN standard practice is to read triggered waveforms from the database into Jiggle Waveform View for picking phases.

The easiest way to read triggered waveforms for an "earthquake" event is to select from the top menu bar: "ModelWaveform source/model...DB Event" (screenshot below) in order to view the waveforms (for an example event with ID 38422815). Notice that in the Status Bar in the bottom right corner, the first box says "DataSource" and the second box says "archdbe@blanchard" which is the source of the triggered waveforms that are displayed (database name @ server name). There are a total of 2760 channels from 433 stations, which is different from the numbers for the continuous waveforms (3743 channels from 659 stations).

Figure

If the settings are different from the ones that are currently set, the dialog boxes below will appear before the waveforms are displayed. First, Jiggle should reload all data for the selected event from database tables (left). Second, the event should be reloaded into Jiggle (right). Click "YES" to proceed in both boxes.

An alternate, more time-consuming, way to selecting "ModelWaveform source/model...DB Event" to display "earthquake" events with triggered waveforms is to edit the Jiggle properties. From the top menu bar, select "PropertiesLoad properties...".

First go to the "TimeWindow Model" tab, select "DataSource" for the "Model Name:" from the drop-down menu, and click the "Set" button (screenshot below): Figure

Next click the "Wave DataSource" tab, and select the "Database" button under the "Waveforms Read From" section, with the "waveform archive copy" value set to 1 (screenshot below). Figure

The dialog box with the following message may appear, go ahead and click "OK".

If the settings are different from the ones that are currently set, the dialog boxes below will appear before the waveforms are displayed. Click "YES" to proceed in both boxes.

Waveform Data Source: Other Options

TODO Explain all options under "ModelWaveform source/model...

Waveform Data Source: Technical Information

Request Card Generator (RCG) determines which channel time windows (which waveforms) to archive for an event, using a ChannelTimeWindowModel for the distance at which an earthquake of a certain magnitude expects to have energy above the noise level. A waveform request is a time window for a single data channel, which is written as a row in the database. The actual waveforms are retrieved and archived by another process, called the WaveArchiver (WA). The waveforms are retrieved from WaveServers, which are port-based services that allow remote clients to request and retrieve chunks of waveform time-series.

SCSN Wiki Pages:

AQMS Trac Pages (with more software details):

TODO Explain ChannelTimeWindowModel

Waveform Viewing: Scroll, Zoom, Filter

TODO Section

Waveform snapshot, view/scroll

Default order by distance from event to station (exception: subnet triggers, which show all stations within the subnet)

Display stations with waveforms on map Picks/amps: stations colored red or orange (TODO figure this out)

Zoom in/out in time

Zoom in/out in amplitude

Apply filter

SCSN standard practice - do not filter before picking, unless the event is really small and filtering is required to properly pick arrivals.

SWARM frame - frequencies

Phase Picking: Arrival Times

TODO Section

P and S, how many, how far?

Pick Description: 4 characters

  • TODO use hotkeys
  • 1) impulsive (i) or emergent (e)? Example screenshots
  • 2) type of phase: compressional (P) or transverse (S)? Example screenshots
  • 3) first motion polarity - compression (c) or dilatation (d)? This can be left blank if the polarity is not obvious. c is first motion up, d is first motion down.
  • 4) Pick quality weight (USGS Standard). Options: 0,1,2,3,4. 0 is best, 4 is worst.
    • Pick quality 0: Full weight of 1. On the obviously correct sample and has a significant rise (very impulsive arrival).
    • Pick quality 1: 3/4 weight. Not certain of the exact sample to place the pick, but has impulsive arrival.
    • Pick quality 2: 1/2 weight. Reasonably certain which half wave the arrival starts on. Arrival is emergent, not impulsive.
    • Pick quality 3: 1/4 weight. Not certain where to place the pick, but the pick is necessary for a good location (e.g. it closes an azimuth gap). Arrival is definitely emergent.
    • Pick quality 4: Weight is 0. Pick quality is very poor, so it is not used for location, but the pick may be used for magnitude calculation.
  • The first and last pick characters are linked. i0,i1,e2,e3,e4. Must have an impulsive arrival to have a pick quality of 0 or 1. See hotkeys.
  • TODO what are weights for trigger? wP.4
  • TODO what do the stars before picks mean?

Picks from AQMS RT -> used to get initial RT location with Earthworm

Expected P and S arrival times (green)

Each station (not channel) should have no more than one P and one S pick.

All automatic picks from RT AQMS must be inspected. The automatic pick must be within one or two samples (for HH channels) of the correct time, so that the first motion is correct.

Any picks retained or inserted on BH or other low data rate channels must be on the correct sample & be assigned a weight lower than 0.

Correct automatic picks occur after the beginning of the seismic energy by at least one sample, sometimes two samples for high sample rate stations.

Auto-picker in Jiggle

Manual picks - should go on the last sample that contains no earthquake energy.

Explain how to do manual pick in Jiggle

Picks have changed -> location will change

View only channels with picks (P)

  • ā€˜Pā€™ show only waveforms with picks -> good way to delete bad picks at faraway stations

Which channels used for picks? Each pick should be on the channel that shows the phase most clearly & accurately. Generally this will be the vertical channel (HHZ) for the P pick, and a horizontal channel (either HHN or HHE) for the S pick, although there may be exceptions.

Distance 120 km limit? - beyond that, location not likely to change much, at least for SCSN which has a large network

Analyst preferences - some will keep RT picks, others will delete all RT picks and use combination of Jiggle auto-picker with manual picks. Different settings in properties files as well.

First motions are saved for later use in focal mechanism calculation (TODO which software does this? - not done in Jiggle) This is generally done for events with M > 3 inside the network, or M > 2.5 if a significant number of first motions are available.

Amps: Peak Amplitudes

TODO Section

View only channels with amps (A)

Amps have changed -> magnitude will change

Which channels used for amps?

Automatic amp selection (solid orange triangles) from RT

Reject amps (hollow orange triangles) - how and why?

Coda

View only channels with coda measures? (C)