Simulation Model To Generate Real-Time Warnings For Tsunami

The Ministry of Earth Sciences (MoES) began efforts to set up a national tsunami early warning system, after the killer waves struck the Indian Ocean on December 26, 2004. On October 15, Minister of Earth Sciences Kapil Sibal unveiled India’s first Tsunami Early Warning System which will issue an alert for the killer wave within 30 minutes of an earthquake. Efforts are being made to reduce the time to 6-7 minutes.

The Warning System has been established at a cost of Rs 125 crore, in collaboration with the Department of Science and Technology (DST), Department of Space (DOS) and the Council of Scientific and Industrial Research (CSIR). The National Tsunami Early Warning Centre (TEWS) has been set up at the Indian National Centre for Ocean Information Services (INCOIS), Hyderabad.

TEWS, is a cluster of several high-end technologies which are applied to generate real-time warnings for killer waves, has been internationally recognised as a technology marvel. Peter Koltermann, Head, Tsunami Co-ordination Unit Inter-governmental Oceanographic Commission, UNESCO, described the system as the most modern in the world during the launch ceremony.
Biztech2 spoke to Shailesh Nayak, director, INCOIS, to get a first-hand look at the technology that drives the entire system.

How the warning is generated

The east and west coasts of India and the island regions are most likely to be affected by tsunamis generated by earthquakes from two potential sources — the Andaman-Nicobar Sumatra island arc and the Makran subduction zone, north of the Arabian Sea.

The Early Warning Centre enables reception of real-time data from sensors, analysis of the data, and generation and dissemination of tsunami advisories following a standard operating procedure. Seismic and sea-level data are continuously monitored in the Centre using a custom-built software application that generates alarms/alerts whenever a preset threshold is crossed.

Data capturing by sensors

TEWS comprises a real-time network of seismic stations, Bottom Pressure Recorders (BPR) and tide gauges. The centre receives real-time seismic data from the national seismic network of the Indian Meteorological Department (IMD) and other networks. “The system detects all earthquakes of more than 6 magnitude occurring in the Indian Ocean in less than 20 minutes of occurrence,” says Nayak.

IMD has established a 17-station Real Time Seismic Monitoring Network (RTSMN). The data through these stations is transmitted simultaneously in real-time through VSAT communication facilities to the Central Receiving Stations (CRSs) located at IMD, New Delhi, and INCOIS, Hyderabad, for processing and interpretation.

BPRs installed in the deep ocean are the key sensors that confirm the triggering of a tsunami. The National Institute of Ocean Technology (NIOT) has installed four BPRs in the Bay of Bengal and two in the Arabian Sea. Real-time tide gauges are also an essential component of the storm surge monitoring system. The data collected is relayed via a communication satellite to the Tsunami Warning Centre.

Real time processing using simulation model

INCOIS has established high-end servers and database for real-time processing of data. To host the mission critical TEWS’s core applications, INCOIS has established two IBM p590 servers, one with 18 POWER 5+ processor cores/186 GB memory and the other one with 16 POWER 5+ processor cores /176 GB memory at the data centre. All the computing resources operate in active-active mode. Says Nayak, “In tsunami-like situations, where more computing resources will be demanded by a particular application(s), those can be dynamically addressed to the IBM server without a stoppage in any of the running services.”

TEWS also consists of a simulation model that has been developed in association with Tata Consultancy Services (TCS). INCOIS has generated simulations of possible scenarios of triggering of tsunami after massive earthquakes. The information about magnitude, location and depth at which an earthquake has occurred is fed into computers which picks up an appropriate scenario and simulates formation of tsunamis.

TCS has used the server and workstation computing resources to generate various scenario outputs. For this purpose IBM XL Fortran Compilers were used to run Fortran programs (N2 Model) using various parameters provided by INCOIS.

Nayak mentioned that in order to have simulations more closer to real-time event, a mechanism of generating scenario outputs from given parameters is also deployed. In fact, one LPAR (logical partition) on the IBM p590 server is entirely dedicated to running the N2 Model with parameters. After the outputs being generated, the custom-built program will load them into the database. All such activities will have options of triggering each activity manually or they can be done automatically, informed Nayak. Various IBM and DELL Intel servers and workstations equipped with latest dual core and quad core processors are also deployed to run other applications like mail services, file serving and custom applications.

A custom-built software application addresses the specific requirements of TEWS. The application is based on J2EE. Tools like IBM Websphere Application Server, IBM Datastage Server, IBM DB2 UDB, Arc IMS, Arc GIS are used for deploying the TEWS applications. IBM Tivoli Storage Manager is used for backup and archiving. INCOIS is also analysing the disaster recovery requirement for the system.

Communication Network

Communication of data from seismic stations, tide gauges and BPRs to the Centre is critical for generating timely warnings, so a host of communication methods are employed. ISRO has made an end-to-end communication plan using INSAT. A high level of redundancy is being built into the communication system.

After analysing the seismic data through simulation model, TEWS disseminates advisories to the Ministry of Home Affairs for dissemination to the public. A satellite-based virtual private network for disaster management support (VPN-DMS) has been established for this. Nayak says, “In case of confirmed warnings, TEWS is equipped with necessary facilities to disseminate advisories directly to administrators, media and public via SMS, email, fax, etc.

During the inauguration of the warning centre, Kapil Sibal mentioned that the efficiency of the system was proved during an under-sea earthquake of 8.4 magnitude that occurred on September 12, 2007, in the Indian Ocean. However, he asked experts to improve the system and further reduce the time for disseminating information to the targeted people.