ALBERT

Description: Although originally not founded nor funded for earthquake monitoring, after the Indian Ocean tsunami disaster in December 2004 this became an important issue for the GEOFON program of GFZ Potsdam. The GEOFON earthquake information system is based on real-time data feeds of the GEOFON Extended Virtual Network (GEVN), a virtual network about 300 stations and many partner network stations distributed globally. The data are acquired by Internet using the SeedLInk real-time protocol, a worldwide defacto standard developed at GFZ. The system provides very timely but nevertheless precise automatic earthquake parameter information published on its web page or by email and SMS alerts. Due to tis expertise, GEOFON was pppointed to design and implement the seismological component of the German contribution to the Indian Ocean Tsunami Early Warning System (GITEWS). Beside the earthquake monitoring and the operation of a major global seismic broadband network GEOFON runs the largest seismological data archive in Europe. In addition, the cooperation and networking of European and other data centers both in terms of real-time data exchange and the setup of distributed data archive structures are promoted and actively supported. Large EU projects like MEREDIAN and NERIES coordinated by ORFEUS are basically relying on GEOFON's innovative concepts and guidance.

Description: In order to improve and extend access to high-quality (broadband) waveform data from European and Mediterranean stations ORFEUS is currently implementing a distributed data archive for continuous broadband waveform data. This is a collaborative effort of four major European data centers: the ODC/KNMI, GEOFON/GFZ, Med- Net/INGV and Geoscope/IPGP within the ORFEUS framework. Data access will be realized through a commonWeb portal. This consortium of data centers will also offer coordinated backup facilities for European-Mediterranean digital waveform data. The Virtual European Broadband Seismic Network (VEBSN) continues to grow rapidly. It provides the basic infrastructure for (near) realtime waveform data exchange in the European-Mediterranean area and involves currently (December 2004) 37 observatories contributing with more than 120 stations. Both continuous and event data is directly available. We will present the new technological developments involved and current discussions on how to facilitate data access and data mining. Also included is the presentation of the new ORFEUS web pages.

Description: After the Mw=9.3 Sumatra earthquake of December 26, 2004, which generated a tsunami that affected the entire Indian Ocean region and caused approximately 230,000 fatalities, the German government funded the German Indian Ocean Tsunami Early Warning System (GITEWS) Project. The GEOFON group of GFZ Potsdam was nominated to develop and implement the seismological component of the GITEWS system. This poster presentation describes the concept of the GITEWS Earthquake Monitoring System (EMS) and reports on its present status and progress of implementation. The major challenge for an EMS within a tsunami warning system is to determine earthquake source parameters in terms of location, size and possibly rupture propagation as quickly as possible, in order to allow counter measures before a potential tsunami may hit coastal areas. Tsunamigenic earthquakes usually occur along subduction zones, which are often close to coastal lines. In the Indian Ocean this is particularly true for the Sunda Trench off the shore of Indonesia and the Macran subduction zone off the shore of Iran. For an Indian Ocean monitoring system where short warning times are a requirement, a dense real-time network of seismic stations in Indonesia is therefore essential. It must be supplemented by a substantial number of stations in other countries surrounding the Indian Ocean. International cooperation and real-time data exchange across political boundaries are essential for successful tsunami warning in the Indian Ocean region. Within the GITEWS project, up to 40 new broadband and strong motion stations are being installed in the Indian Ocean region until 2010. Up to 22 new stations are set up in Indonesia and another 18 stations distributed over Sri Lanka, Maldives, Yemen, Kenya, Tanzania, Madagascar and Israel. Real-time communication is provided by private VSAT communication systems. Another challenging task within the GITEWS project is the design and implementation of efficient and fast acquisition and processing software. Based on an innovative software architecture and code, the SeisComP 3 software package has evolved from the widely used SeisComP 1 and 2 packages developed earlier by GEOFON. It combines real-time data acquisition and quality control with automatic procedures to determine location, depth, magnitudes and other source parameters. Sophisticated alert and visualization tools provide a variety of front ends. The basic parameter calculation is done fully automatic by the software. Acoustic and optical alert tools are implemented to guarantee the attention of the seismic experts in the warning center. Operators can intervene and correct automatic results to accelerate the automatic processing and to improve location accuracy. Since May 2007, SeisComP 3 is being used as the primary processing software at the Indonesian Warning Center BMG for tsunami warning purposes. The current version of the software implements a newly-developed rapid and robust regional magnitude calculation. Since it installation in Indonesia in early May 2007, SeisComP 3 has provided realistic magnitude estimates allowing assessment of an earthquake's tsunami potential and possibly warning by BMG in less than 5 minutes. The SeisComP 3 earthquake monitoring system at BMG is already connected to similar systems in Germany, the Maldives and the Republic of Yemen, for exchange of seismic waveforms and earthquake parameters in real-time. Other countries in the Indian Ocean region will follow as soon as data from their seismic stations become available. There is also interconnection between the GITEWS and the Northeastern Atlantic and Mediterranean Tsunami Warning System (NEAMTWS).

Description: In 2008 GFZ Potsdam has started to operate its global earthquake monitoring system as an experimental seismic background data centre for the interim NEAMTWS (NE Atlantic and Mediterranean Tsunami Warning System). The SeisComP3 (SC3) software, developed within the GITEWS (German Indian Ocean Tsunami Early Warning System) project was extended to test the export and import of individual processing results within a cluster of SC3 systems. The initiated NEAMTWS SC3 cluster consists presently of the 24/7 seismic services at IMP, IGN, LDG/EMSC and KOERI, whereas INGV and NOA are still pending. The GFZ virtual real-time seismic network (GEOFON Extended Virtual Network - GEVN) was substantially extended by many stations from Western European countries optimizing the station distribution for NEAMTWS purposes. To amend the public seismic network (VEBSN – Virtual European Broadband Seismic Network) some attached centres provided additional private stations for NEAMTWS usage. In parallel to the data collection by Internet the GFZ VSAT hub for the secured data collection of the EuroMED GEOFON and NEAMTWS backbone network stations became operational and the first data links were established. In 2008 the experimental system could already prove its performance since a number of relevant earthquakes have happened in NEAMTWS area. The results are very promising in terms of speed as the automatic alerts (reliable solutions based on a minimum of 25 stations and disseminated by emails and SMS) were issued between 2 1/2 and 4 minutes for Greece and 5 minutes for Iceland. They are also promising in terms of accuracy since epicenter coordinates, depth and magnitude estimates were sufficiently accurate from the very beginning, usually don’t differ substantially from the final solutions and provide a good starting point for the operations of the interim NEAMTWS. However, although an automatic seismic system is a good first step, 24/7 manned RTWCs are mandatory for regular manual verification of the automatic seismic results and the estimation of the tsunami potential for a given event.