The “TRUAA” Seismic Network: Upgrading the Israel Seismic Network—Toward National Earthquake Early Warning System

Abstract Following the recommendations of an international committee (Allen et al., 2012), since October 2017, the Israeli Seismic Network has been undergoing significant upgrades, with 120 stations being added or upgraded throughout the country and the addition of two new datacenters. These enhancements are the backbone of the TRUAA project, assigned to the Geological Survey of Israel (GSI) by the Israeli Government, to provide earthquake early warning (EEW) capabilities for the state of Israel. The GSI contracted Nanometrics (NMX), supported by Motorola Solutions Israel, to deliver these upgrades through a turnkey project, including detailed design, equipment supply, and deployment of the network and two datacenters. The TRUAA network was designed and tailored by the GSI, in collaboration with the NMX project team, specifically to achieve efficient and robust EEW. Several significant features comprise the pillars of this network:Coverage: Station distribution has high density (5–10 km spacing) along the two main fault systems—the Dead Sea Fault and the Carmel Fault System;Instrumentation: High-quality strong-motion accelerometers and broadband seismometers with modern three-channel and six-channel dataloggers sampling at 200 samples per second;Low latency acquisition: Data are encapsulated in small packets (<1 s), with primary routing via high-speed, high-capacity telemetry links (<1 s latency);Robustness: High level of redundancy throughout the system design:Dual active-active redundant acquisition routes from each station, each utilizing multicast streaming over an IP security Virtual Private Network tunnel, via independent high-bandwidth telemetry systemsTwo active-active independent geographically separate datacentersDual active-active redundant independent automatic seismic processing tool chains within each datacenter, implemented in a high availability protected virtual environment. At this time, both datacenters and over 100 stations are operational. The system is currently being commissioned, with initial early warning operation targeted for early 2021.