Quarterly Updates
April - June 2006

The headline for our second newsletter of 2006 is the departure of Maiclaire Bolton. Maiclaire joined the ISC at the end of 2003 as a seismologist, editing the ISC Bulletin. After a few months training she mastered the editing work with great commitment whilst gaining wide seismological knowledge.

During her time here the ISC significantly upgraded its operational capabilities and its technology which initially entailed a much greater work load for the ISC Bulletin editors. With much skill and dedication Maiclaire ensured the timely publication of the Bulletin, despite all difficulties.

At the end of June, after almost 3 years with the ISC, Maiclaire returned to her homeland Canada to take on new challenges and to foster her career in seismology. We wish her great success and happiness in her professional and personal life.

The new Emergency Management Analyst for Seismic Hazard reporting to the Government of British Columbia, Canada – Maiclaire Bolton

At the beginning of June, the ISC Executive Committee (EC) came to Thatcham for its annual meeting. The EC, chaired by Dr. Gary Gibson, reviewed the Director's report (available on the ISC web pages) and accounts for the year 2005 and discussed future plans. Following presentations from the Director and staff, the EC formulated a number of action plans including: Publish a new information brochure; Compile information about the practice applied by different seismological institutions in picking arrival times and measuring amplitudes that are contributed to ISC; Implement the recommendations of IASPEI for magnitude determinations; Investigate the possibility of introducing a threshold magnitude to the edited ISC Bulletin.

ISC was encouraged by the committee to strengthen cooperation with international organizations in particular with UNESCO, WMO and the CTBTO. The staff members were also recommended to take part in the activities of the coming UN 2008International Year of Planet Earth. The EC approved ongoing efforts by ISC to modernize earthquake location procedures, including the use of the K135 travel time model, to upgrade network and station coding scheme and replace old computer systems.

The EC further encouraged the ISC to add reviewed information from the old ISS bulletin to its database.

After reviewing the ISC’s financial situation, the EC approved the recruitment of two new seismologists to join Dmitry Storchak and Beatriz Vera with the goal of significantly reducing the gap between the time of earthquake occurrence and the time of publication of the reviewed earthquake information. At the time of writing this recruitment is complete. Also in this respect, I would like to remind all users of the ISC Bulletin that earthquake information, including phase readings, are available on-line, as soon as they are made available to ISC.

Following the recommendations of the EC the ISC is studying an amendment to its thresholding rules. These have been required since the data collection was expanded to include any size of included in manual review are:

• Any magnitude of 3.5 or higher from any agency
• Recorded at a distance of at least 10 degrees from the assumed epicentre
• Reported by at least two agencies

An event has only to meet one of these criteria. The proposed alteration would put a minimum magnitude on those events that are recorded by two or more agencies. Although many agencies find the ISC Bulletin very useful in providing revised locations using data from just across the borders of their country, the location of small local events using global velocity models should be considered with care. Many of these may be small quarry blasts. It is as a consequence of this that only events with a magnitude of 2.5 (for instance) would be considered for manual review and possible relocation. We would appreciate any comments on this proposal before it is implemented for the review of January 2005 data. Please send your comments to avi@isc.ac.uk.

With these conditions in mind, ISC DOES NOT refuse small earthquake data.

During his stay in the USA for the SSA-2006 meeting, Avi Shapira paid a visit to the National Earthquake Information Center (NEIC) of the US Geological Survey. Discussions were held with the seismologists at NEIC, covering a wide spectrum of issues of interest to both ISC and NEIC. It was tentatively agreed that such coordination meetings between the international data centres, including NEIC, ISC and EMSC and others should be conducted periodically. Sincere thanks go to the USGS for facilitating this visit and for their kind hospitality.

Dmitry Storchak participated in the meeting of the European Geophysical Union in Vienna and combined it with a visit to the IDC of CTBTO where different ways of using ISC Bulletin were discussed.

Avi Shapira and Maiclaire Bolton participated in the annual meeting ofthe Seismological Society of America which included the commemoration of the 100th anniversary of the San-Francisco earthquake. Avi and Maiclaire presented up-to-date reports on the activities of ISC. We thank the Geophysical Institute of Israel for supporting Avi's participation.

Upon the invitation of UNESCO, Avi took part in the meeting of the RELEMR countries in Malta. One of the main topics of that meeting referred to the use of ISC data as a basis for compiling an earthquake catalogue of events relevant to the participants for 1900-1998.

We are pleased to report that the University of the West Indies, in Kingston, Jamaica has joined the ISC as a member, following years of being a devoted data contributor.

The second new member to join the ranks of the ISC Governing Council is the Institute of Geophysics of the Polish Academy of Sciences. New members are always very welcome.

A relatively new data contributor is the Iraq Seismological Network (ISN). Starting in 2005, ISC has received data from the Iraqi seismological network that was established in 1977 as a unit within the Scientific Research Council, Building Research Center. ISN consist of five Observatories; Baghdad, Mosul, Sulymania, Rutba and Basrah. All stations are equipped with both analogue and digital recorders. In the late eighties, the ISN was transferred to the Iraqi Meteorological Organization which became the Iraqi Meteorological and Seismology Organization.

The main objective of ISN is to provide the monthly earthquake bulletin but it is also used for conducting research programs in the field of earthquake engineering and engineering seismology. Recent studies involve site response evaluations for a number of vital projects in Iraq, such as dams, thermo-electrical plants and bridges.

Fig. 1 Iraq Seismological Network

Further new data contributors are the Institute of Geophysics at the University of? Tehran (TEH), which operates the Iranian Seismological Centre.

The Iranian Seismic Telemetry Network was founded in 1995 and it is the first modern seismic network of Iran. All hardware and software were bought from Nanometrics Inc. of Canada.

The Network is equipped with 3-component short period seismographs grouped in 10 sub-networks distributed over a large part of the country. These sub-networks are the Esfahan, Kermanshah, Mashad, Mazandaran, North of Khorasan, Semnan, Shiraz, Tehran, Tabriz and Yazd networks. The Institute of Geophysics initiated its efforts by installation of the first group of the sub-networks in the Tabriz and Tehran regions in 1995. The Kermanshah Network is the most recent of the sub-networks, having been launched in 2003.

Fig.2 Iranian Seismic Telemetry Network

The data are recorded with a rate of 50 samples per second and processed in real time by using NAQS (Nanometrics Acquisition System). The data are recorded on a ring buffer that keeps the data for one week. When at least four stations detect an event, a triggering system is activated and records the event data permanently on a hard disk.

The Network reports ML, and Mn (Nuttli,1973) magnitudes.

From January to June 2006, ISC was pleased to host Hoang Seung Kim from the Korean Meteorological Agency. During his stay, Kim was trained in using ISC location procedures through the re-location of Korean earthquakes using different travel time models, different location algorithms and weighting schemes. Kim was acquainted with the ISC relational data base. We enjoyed having Kim with us and we trust that he benefited from his stay and that his visit will strengthen the cooperation between KMA and ISC.

Hoan Seung Kim returns home