CTBTO Link to the ISC Database...$ The CTBTO Link to the ISC database is an exclusive service " funded by the IDC/CTBTO, " provided by the ISC, " used by NDCs and PTS. $ The Link gives

CTBTO Link to the ISC Database

June 24, 2015 S&T, CTBTO, Vienna 1

Dmitry A. Storchak, Kostas Lentas, James Harris

International Seismological Centre (ISC) www.isc.ac.uk

June 24, 2015 S&T, CTBTO, Vienna

Thanks to the international and non-governmental status, the ISC is now able to collect seismic bulletins from 137 agencies worldwide, including JMA, USGS, USArray and IDC / CTBTO.

2

2015

International Seismological Centre (ISC): Intro


Jointly with USGS, the ISC runs the International Seismographic Station Registry

3

By 2015, a total of ~21,500 stations were registered; ~7,500 of them contributed to the 2012 ISC Bulletin.



Global long-term definitive Seismic Bulletin (1904-2015)

4

~5.7 M events, ~1.9 M of them are reviewed; ~141 M seismic arrivals from ~15,900 stations



Seismic arrays and stations of IMS Arrays and stations reporting to ISC Number of stations that

contributed to the location of events common to

REB and ISC bulletins



Comparative magnitude

completeness of the three global

bulletins

1

10

100

1,000

10,000

100,000

-1.0 0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0

Num

ber o

f eve

nts

magnitude

2010-‐2012

NEIC

IDC

ISC



IASPEI Reference Event List (GT)

7

8,573 GT(0-5) events with locations known with 95% confidence level: ü  natural ü  anthropogenic accompanied by ~870,000 associated seismic arrivals


1959-2012

q  The Link is a service provided to NDCs and PTS from the secure IDC website.

q  The ISC designs, implements and maintains this service in consultation with the IDC.

q  The Link is funded and technically assisted by CTBTO.


CTBTO Link to the ISC Database: Intro

q  Provide specifically designed web tools to access ISC datasets: §  ISC Bulletin; §  Station Registry §  EHB Bulletin; §  GT-List (Ground Truth).

q  Assist in preparing waveform requests to non-CTBTO waveform archives with respect to REB and GT events.

q  Allow flexible event re-location using REB and ISC data

q  Give a historical perspective into current IMS observations based on the wealth of non-IMS recordings over the last 50-100 years.


CTBTO Link to the ISC Database: Objectives


The Link: secure IDC website, where to find click on Civil & Scientific

click on Links

Four groups of searches:

●  Area based – spatio-temporal searches within the ISC Bulletin;

●  REB event based – spatio-temporal searches based on specific events within the IDC Reviewed Event Bulletin;

●  IMS station based – searches of station data proximate to a particular IMS seismic station.

●  GT event based – searches for GT event waveform records.


The Link: Overview of searches

q  Interactive Google Maps based interface; q  One of the most flexible and

sophisticated interactive tools available to the seismological community;

q  Searches can be completed across multiple meridians;

q  Highly customised shapes unavailable on any other seismological site.

q  Customised overlays: q  Plate boundaries; q  Seismicity (with clickable data);

q  Station markers (with clickable data).


The Link: Convenient interactive web service

Links to a full Bulletin for a selected event

5 categories of events to choose

4 event types to choose

Korea region, 2006-01-01 to 2009-12-31


The Link, Example 1: Event types

Sortable columns

Korea Region

§  All networks reporting events are listed

§  For each network: o  timelines of the event

numbers, o  frequency-magnitude

distributions


The Link, Example 2: Reporting networks

Based on the selected REB event:

Stations reporting for other events within the magnitude tolerance AND the selected REB event

Stations reporting for events within the magnitude tolerance yet NOT the selected REB event


The Link, Example 3: Missing stations

IMS station based: e.g. pre-IMS history of WRA

The station search also provides historic data for stations before they became part of the IMS network or stations that were operated for many years close to current IMS sites.

IMS upgrade


The Link, Ex. 4: Station features

distance

Arriv

al .me resid

ual

Median resid

ual

Observa.o

ns

Year

Median resid

ual

Observa.o

ns

Year


Link, Ex. 5: REB: non-IMS waveform preview & request Select an area and a time period

Select an REB event

Closest stations to the event in Peru, Apr 01, 2015, 16:45

Waveform previews for individual stations with

close range view showing raw and pre-

filtered waveform Web form for ordering waveforms from: •  IRIS DMC, •  GeoNet (GNS) •  EIDA (ORFEUS)


The Link, Ex. 6: ISC-style web location for REB events Same event in Peru, 01-04-2015 As usual, the ISC will compute, review and publish its hypocenter and magnitude solution only in 2 years time when all possible arrival times have been collected from ~137 institutions worldwide.

In the mean time, there are hundreds of arrival times from IMS and non-IMS stations already available in the ISC db. Using the Link, users can compute an ISC-style location, having selected which seismic stations/phases are to be used as defining.

The result can be obtained almost instantaneously using an advantage of the ISC Locator accustomed for non-uniformly distributed seismic networks. IMS formatted output is ready to be used for further analysis.


The Link, Ex. 7: GT events: waveform preview & download §  We collected waveforms of GT events for the

period 1990-2012 from IRIS DMC and EIDA. §  We are planning to collect all available

waveforms from many other archives for the entire digital period: 1980-present.

Having selected a specific GT event, user can preview original and pre-filtered waveform snippets as well as download all waveforms for this event to their computer.


The Link: Current Use

Statistics of the Link’s use by the PTS and NDCs

The Link: Acknowledgements


funding, providing REB, connecting to NDCs, and development advice

To 63 Member-Institutions and 137 bulletin providers

stable, convenient and open access to seismic waveform records

excellent open software

crucial start-up funding and current support

u  The CTBTO Link to the ISC database is an exclusive service q  funded by the IDC/CTBTO, q  provided by the ISC, q  used by NDCs and PTS.

u  The Link gives a historical perspective into current IMS observations based on the wealth of non-IMS recordings over 50-100 years.

u  The ISC continues further improvement of the Link under the new Contract.

The Link: Summary


Documents

CTBTO Link to the ISC Database...$ The CTBTO Link to the ISC database is an exclusive service " funded by the IDC/CTBTO, " provided by the ISC, " used by NDCs and PTS. $ The Link gives