Page
1 - Event Selection, Step 1
WILBER
II allows you to select from a catalog of events for which ORFEUS
has event based data. To begin, select a time period from the quarterly
list (example at right) to display a map showing that quarter's seismic
events. The default time period is the last 90 days.
You
can view all events for your selected quarter or view a subset
of events within a given radius from a selected event. The default
radius is 5 degrees but you can select up to 60 degrees for your search.
How does this help? If you have several events that occurred in the
same geographic area it will be hard to select just one of them from
the map. The radius selection narrows down your list of events from
which to choose (on the next page). You may also be interested in seeing
how many events occurred within a certain radius of another event.
Once you
have selected a spot on the map or clicked the link for all events,
the list of events will be presented on the next page.
Page
2 - Event Selection, Step 2
Here you
should see a list of events from which to choose. For event selection
we used alerts/bulletins from the NEIC,
EMSC and
VEBSN. Example:

A change
in color of the listed events means they are different events. Listings
of the same color that appear together (like the two JAVA events listed
above) are considered the same event. Clicking on an event link takes you
to the next page.
Page
3 - Report of Networks with Responding Stations
This page gives an overview of available data by network. The reason for this
is that the sheer volume of available stations can be overwhelming and clumsy
to navigate. Therefore, this page allows you to limit what stations are displayed
during the data selection to the networks of your choosing (example at right).
The number of stations for which there is data available
for each network is listed in the right-hand column. You can select
ALL networks or individual networks. Once you have made your selections,
click the "Proceed" button to continue.
Page
4 - Station Selection, Waveform Browsing, and Requesting Data
Page 4 will display all of the stations in the network(s) you selected on the
previous page. The list of stations also includes stations for which the
network(s) you selected are secondarily affiliated. If this is the case some
stations might be displayed which do not appear to be from the selected
network(s); this is because stations are always shown with their primary
network displayed. Here is an example of a station list:

You have
the option of sorting the list of stations by distance from the event
(default), station code (alphabetical), or by network if more than one
network was selected on the previous page. There is also a map of responding
stations available for viewing (link in upper right corner).
Stations
are listed as STATION_CODE.[LOCATION_CODE.]NETWORK_CODE (the location
code is only displayed if it exists) with their distance
and azimuth from the event listed below them. Clicking on a station
name will launch a Java applet version of SeisGram2K
that displays waveforms from all available channels for that station.
Clicking
on the checkbox next to a station name means that you want to include
that station in your final request for data. You can select ALL stations
to be included; ALL stations for just selected networks; or individual
stations. If you select ALL, any other boxes you have checked will be
ignored. If you have selected ALL for a given network (or networks),
you may still select individual stations from other networks and they
will be included in your request. In the example image above, the
user has selected to include all stations from the IC network and one
station from the UW network in the request.
Scrolling
down the screen you will see a list of available channels. This list
is a compilation of all channels for all of the stations on the page.
To determine what channels are available for a given station, browse
the seismograms for that station and the channels are listed at the
top of the browse window.

In the
example above, the user has selected all of the broadband channels (B??),
all of the vertical channels (??Z) and one north-south channel (SHN).
For illustration, red circles have been drawn around the channels that
will be included in the request based on the user's selections. If you
use the wildcard options (those with ??), only seismic channels will
be selected. (If you need help
with channel descriptions, please review Appendix A of the SEED
manual.)
At the
bottom of the page we see the available output options. The default selection
is SEED.
(See descriptions
of the output options at the end of this file.) Next, select the
time window for your data request. Limits are ~5 minutes before and
~1.5 hours after the P-phase arrival, depending on the available data
Now
that the data selection has been made, the user is ready to fill in personal
information to uniquely identify the request.The User Name is required
and used to create a personal directory in the public FTP area on the ORFEUS
server. The Request Label is also required and will be used to name the
data product. If you are requesting several data sets, you might want to use
something more descriptive such as location or time. Both of these fields are
mandatory. If you would like to be notified by email when your request has been
processed, you will need to fill out the last field and click the checkbox
(as shown in the example). Click the "Process Request"
button at the bottom of the screen when you are satisfied with your
entries. Your data request will be submitted to the ORFEUS server
for processing.
Page
5 - Request Status (or "What happens when you make a request?")
After you
click the "Process Request" button, you will be shown the
status of your request. There is a queue for requests in progress
and you will be told where you are in the queue. In this example, the
user is #1 in the process queue (first column). The number of lines
in the request file are shown to give all users an idea of how big a
request is. Finally, the last column shows the number of minutes the
request has been in the queue.

The queue
moves very quickly unless there is a process that is faltering for some
reason. If there is a problem with a request, the user will be notified
on screen and the request will be removed from the queue. Removing
a request from the queue means that other requests can move up to be
processed. Below is an example of a Request Description that
appears in the status window:

You
don't have to wait for your request to be processed before leaving the
status window. If you want to request data from other events, simply
navigate back to start (home) or go back to your chosen list of events
(link at the top of page 4) to make another request. Your data will
be waiting in the FTP directory for you to pick up at your leisure.
The data is kept for 1 week before it is discarded.

If you
watch the prompts (your screen will automatically update every 20 seconds),
you'll eventually see the message above. Notice that the path to
a personal data directory is listed and linked at the bottom. If
you choose not to wait for this prompt, you can go to ftp://www.orfeus-eu.org/pub/wilberII/userdata/<your
user name> to collect your data whenever you're ready, as long
as it's within one week of the request. If you choose to be notified
by email, the link will be included in the notice.
Still confused?
Please contact us at
and we'll be happy to help you.
Thank you
for trying WILBER II!
SEED
The Standard
for the Exchange of Earthquake Data (SEED) is an international standard
format for the exchange of digital seismological data. SEED was designed
for use by the earthquake research community, primarily for the exchange
between institutions of unprocessed earth motion data. It is a format
for digital data measured at one point in space and at equal intervals
of time. See Chapter 1 of the SEED
manual for more details.
miniSEED
The term
Data Only SEED Volumes (Mini-SEED) has come to be used to identify
SEED data records without any of the associated control header information.
(Mini-SEED is a compact way to work with waveform data.) Data Only
and Dataless SEED volumes are to a certain extent the two parts of
a complete SEED volume. Only Time Span Control Headers are not included
in either of these components, however Time Span Control Headers can
be derived from the Data Only SEED. You need a dataless SEED volume
(header information) to make a full SEED volume. See
Appendix G of the SEED manual for more details.
SAC
BINARY or ASCII
SAC2000
is a program to examine, analyze, and plot data. This data is stored
on disk as SAC data files. Each data file contains a single data set.
For seismic data this means a single data component recorded at a
single seismic station. For details about SAC data files, please refer
to the Lawrence Livermore National Labs Web site: http://www.llnl.gov/sac/.
The only difference between SAC binary and ASCII files is the file
type. The ASCII files are white space delimited.
file
names look like so: 2003.185.07.20.58.3718.MN.BNI..BHE.D.SAC_ASC
(year.jday.hour.minute.seconds.sec.network.station.locationID<may
be empty>.channel.qualityID.format)
- individual
files - one file for each station/channel requested, no compression
- TAR
file - all of the individual files collected in one TAR file
- gzipped
TAR file - TAR file compressed using the gzip utility
- compressed
TAR file - TAR file compressed using the UNIX compress utility