Summary: A study on warning algorithms for Istanbul earthquake early warning
and Mustafa Erdik1
Received 13 November 2008; revised 19 January 2009; accepted 26 January 2009; published 21 February 2009.
 17 August (Mw 7.4) and 12 November 1999 (Mw 7.2)
earthquakes have caused major concern about future
earthquake occurrences in Istanbul and in the Marmara
Region. Stress transfer studies and renewal model type
probabilistic investigations indicate about 2% annual
probability for a Mw = 7+ earthquake in the Marmara Sea.
As part of the preparations for the expected earthquake in
Istanbul, an early warning system has been established in
2002. A simple and robust algorithm, based on the
exceedance of specified threshold time domain amplitude
and the cumulative absolute velocity (CAV) levels, is
implemented for this system. Rational threshold levels
related to new bracketed CAV window approach (BCAV-W)