Israel has selected Ottawa, Canada-based Nanometrics to build an earthquake early-warning system in Israel. The alert system will give a 10-to-30-second alert of an impending earthquake. The system’s success depends on the distinction between two types of waves an earthquake generates — P waves (for primary) and S waves (for secondary).
A P-wave is a compressional wave which makes the rock vibrate parallel to the direction of its movement. Since it is a very fast wave traveling through rock at between four and seven kilometers per second, the P-wave is the first wave to arrive at a recording station following an earthquake.
An S-wave, on the other hand, has a shearing motion that makes the rock vibrate perpendicular to its path. This movement slows the S-wave, so that it travels at two to five kilometers per second, or about half the speed of the P-wave.
It is S waves which are almost entirely responsible for the damage and destruction associated with earthquakes.
Depending on different variables, the interval between P waves and S wave can be as short as five seconds or as a long as 25-30 seconds.
Haaretz reports that Nanometric, which won the bid to install the system with and its Israeli partner Motorola Israel, is expected to take a year to have the system fully functional at a cost of $9.8 million.
Jewish Press reports that the system will consist of 120 sensors in three earthquake-prone areas: the Dead Sea valley, the Jordan Valley, and the Haifa area. Sixty-five of the sensors will be new, and fifty-five will be be upgraded existing sensors already in service.
When the sensors detect the P wave, they will automatically feed the information to two command and control centers, which will issue a warning before the S wave arrives.
Israel already has a rudimentary seismic early-warning system, but five years ago the government decided to upgrade the system.
The installation of the system will begin this summer.
Initially the alert system will be connected to educational institutions. It will then be expanded to power stations and other critical infrastructure. In the third stage, it will provide warning to the general public.
In the first stage, the warning will be issued through
In its early stages, the system will provide warnings using loudspeakers, but will later be expanded to have warning issued on various platforms.
The goal is to provide enough time for people to enter secure rooms or leave for open areas, while allowing critical infrastructure to shut down.
Haaretznotes that only a few countries have a nationwide early-warning system for earthquakes. The budget outline the Trump administration submitted to Congress would eliminate for an early-warning system for the U.S. West Coast.
Israel has decided to build such a system because most buildings in Israel are not built to a code which would allow them to withstand powerful tremors, an especially worrisome problem since the country sits astride the Dead Sea rift fault line, which is part of an active fault running from East Africa to Syria.
This article is published courtesy of Homeland Security News Wire.