January - March 2004

Contents

Avi Shapira arrives at ISC
Workshops and Visitors
Station Registration
Bulletin of 2001 is published
ISC phase names are set to conform to IASPEI Standard

Avi Shapira arrives at ISC

Dear Colleagues,

This is my first letter to you as Director of the ISC. I would like to take this opportunity to thank you collectively and individually for selecting and approving my appointment. I do not like to make promises except that I shall do my best to serve the ISC and the supporting seismological community.

I trust that I can speak for all of you when expressing our thanks and gratitude to Raymond Willemann, former Director of the ISC, for the excellent job he did. I can definitely testify to the fact that the ISC under Ray's leadership has made a big step into the 21st century through automating many of the ISC tasks and by providing additional processing tools for the seismologists. Again - thank you Ray.


During the first 3 months of my stay at the ISC I have come to know and appreciate the professionalism and dedication of the staff. The high quality products of the ISC, presented over the years in the form of earthquake bulletins and catalogues, are primarily to be attributed to the efficiency and the highly qualified administrative, technical and seismological staff of the ISC.

Our auditors, Griffins Ltd., have conducted their annual audit and agreed that the 2003 ISC accounts, presented by Maureen Aspinwall, ISC's Administration Officer, are a true and fair statement of the financial affairs of the ISC.

In the first quarter of 2004, Dmitry Storchak, Nurcan Ozel and Maiclaire Bolton have completed the review of the earthquake bulletins up to the end of April 2002. Subscribers will shortly be receiving the printed 4-monthly bulletin for 2002 Jan-Apr and the CD with the updated earthquake files. The training of our new seismologist, Maiclaire Bolton, is in very good progress and thus, we expect to shortly catch up with the original review scheme and provide the Bulletins closer to the time of occurrence of the events.

The main reason for the delay between the time of occurrence and the publication of the bulletin is attributed to the time when the data from the seismological organisations are made available to us. In that respect, I should add that Peter Dawson, who amongst other duties is also in charge of properly parsing your messages, and myself, will be most grateful if contributors are careful when sending data ensuring that it arrives in the right format and that their seismic stations are registered properly in the International Station Registry.

We are approaching the final stage of implementing the new ISCloc program in the routine operation of the ISC. Richard Luckett, Dmitry Storchak, Peter Dawson and James Harris are designing and developing the tools to integrate ISCloc into the interactive editing and review processes.

A new development in the ISC's routine operation is the adoption of the regionalization scheme that the IASPEI working group has proposed and was endorsed by IASPEI in its general assembly in 1991. ISC's systems engineer, James Harris will hopefully implement the new regionalization in the upcoming CD of earthquake data.

Matthew Evans, a Ph.D. student of Leeds University, is completing his research at the ISC on S-splitting of SKS waves. A prototype web interface to distribute results has been designed and is located at: www.isc.ac.uk/SKS. Please e-mail any comments or feedback you may have to matt@isc.ac.uk.

In February 2004 I conducted meetings with the Earth Sciences Division of UNESCO and with the European - Mediterranean Seismological Centre, both located in Paris. An understanding was reached that the co-operation between ISC and UNESCO should strengthen and different practical alternatives should be explored. The meeting with EMSC was devoted to the co-ordination of activities and future co-operation. Both EMSC and ISC realize that the name coding of seismic stations should be reviewed and possibly changed. This alternation should be co-ordinated with other seismological centres such as IDC/CTBTO and NEIC/US Geological Survey. A meeting with NEIC is planned for the summer of 2004.

Avi Shapira
Director

Workshops and Visitors

During January 2004, Avi Shapira participated in a regional seismological workshop held in Aqaba, Jordan. The Aqaba workshop attracted the participation of most of the Middle East and North African countries. The meeting has triggered the interest of representatives from seismological institutions of those countries. We hope that this will be followed by new members to the ISC and additional seismological data from seismic networks.

During the last three months we were privileged to meet with operators of seismic stations in Turkey, Ukraine and Israel who were trained by our neighbour Dr. C. Güralp, of Güralp Systems, Aldermaston, UK.

We also had an important visit by Mr. V R Gordon and Dr K N Danilenko of the Russian Ministry of Atomic Energy. We demonstrated the products and work of the ISC to our guests and learned about the seismological tasks of the institution they represented.

From left-right: V.Gordon, K Danilenko, D Storchak and A. Shapira

We were honoured by a visit from John Young of the UK's AWE Blacknest. Mr. Young had chaired the IASPEI working group on regionalization and briefed us on this issue.

ISC seismologists have attended seismological meetings and lectures at the Earth Sciences Department of Oxford University and the British Society for Earthquake and Civil Engineering Dynamics.

Maureen Aspinwall

Station Registration

The International Registry of Seismograph Stations facilitates exchange of data between networks by identifying seismic stations anywhere in the world with a unique 3 to 5 character code. The Registry is maintained jointly by the ISC and by the World Data Center for Seismology, Denver, which is operated by US National Earthquake Information Center (NEIC).

An on-line station book has been developed as a new service for the International Registry of Seismograph Stations at the ISC and can be accessed at www.isc.ac.uk/IR/index.html. Features of the station book include alphabetic listings of the Registry by station code, name or region and searches can be made for a code or for stations within 200 km of a specific point.

This service complements the online station registration service added at the end of 2003, www.isc.ac.uk/IR/reg.html. The station book was developed to be similar to the station book of the International Registry online at the NEIC, http://gldss7.cr.usgs.gov/neis/station_book/station_book.html. The web based station book is in addition to the existing distribution of an ASCII text file of the station book through the FTP site and on the ISC CDs.

It was expected that this would be an important addition to the ISC's web services and in the first 3 months over 200 hits on the main page and over 400 different listings have been requested, which is already 10 times the number of station lists downloaded via FTP in 2003.

James Harris

Bulletin of 2001 is published

The manual review of 2001 ISC Bulletin is now complete and the data are available from the annual CD-ROM. Approximately 42 thousand out of about 191 thousand reported seismic events were manually reviewed by the editors.

For the first time in its history the ISC used S-arrival times for location. The advantage is mostly visible for small events, where previously the number and azimuthal coverage of reporting stations were often not sufficient to achieve a free ISC location or even a location with a fixed depth. Overall as many as 85% of all reviewed events for 2001 were relocated by the ISC, based on all collected station reports of P and S.

As expected, S-arrivals provided a better constraint on the event depths. In particular, the ISC free depths determinations in 2001 became more consistent with pP-P reports.

ISC phase names are set to conform to IASPEI Standard

After numerous consultations with the seismological community the new Standard Seismic Phase List was finalized by the IASPEI Working Group, chaired by the ISC's Senior Seismologist Dmitry Storchak. Other members of the WG were Johannes Schweitzer, Peter Bormann, Bob Engdahl, Brian Kennett, Jens Havskov and Robin Adams. The list was adopted by the IASPEI General Assembly in Sapporo in July 2003. The article describing the list was published in Nov/Dec 2003 issue of Seismological Research Letters.

The new nomenclature is in tune with popular global travel-time models and reflects significantly increased detection capabilities of modern seismic sensors and arrays. It accounts for improved possibilities of proper phase identification by means of digital multi-channel data processing and modelling the observations with synthetic seismograms. The new standard is meant to limit the uncontrolled growth of ambiguous parameter data.

The ISC's seismologist-developer Richard Luckett has made sure that with introduction of the new location program into the operation, the ISC phase identifications would conform to the new standard.

The ISC data contributors are now encouraged to support the ISC by following the new nomenclature.

Dmitry Storchak