Evaluation and optimization of seismic networks and algorithms for earthquake early warning – the case of Istanbul (Turkey)

Abstract

[1] Earthquake early warning (EEW) systems should provide reliable warnings as quickly as possible with a minimum number of false and missed alarms. Using the example of the megacity Istanbul and based on a set of simulated scenario earthquakes, we present a novel approach for evaluating and optimizing seismic networks for EEW, in particular in regions with a scarce number of instrumentally recorded earthquakes. We show that, while the current station locations of the existing Istanbul EEW system are well chosen, its performance can be enhanced by modifying the parameters governing the declaration of warnings. Furthermore, unless using ocean bottom seismometers or modifying the current EEW algorithm, additional stations might not lead to any significant performance increase.

Rapid Estimation of Earthquake Source and Ground-Motion Parameters for Earthquake Early Warning Using Data from a Single Three-Component Broadband or Strong-Motion Sensor

“…This procedure is problematic, because an adequate database containing the records of both moderate and large earthquakes over a wide range of source-to-site distances is unavailable for most seismic-active regions around the world, leading to large data gaps and thus uncertainties in the algorithms. Some authors have suggested filling these gaps with simulated waveforms (e.g., Zollo et al, 2009;Oth, Böse, et al, For each earthquake, we show the results at two stations at distinct epicentral distances Δ. From top to bottom the panels show the corresponding seismic records and results for classification (output should be 1 because Δ km ≤ 15M), magnitude M, peak ground velocity (PGV), and distance Δ.…”

Toward a Loss-Driven Earthquake Early Warning and Rapid Response System for Kyrgyzstan (Central Asia)

“…For more information on this methodology and the exact definition of the cost function, we refer the reader to Oth et al (2010) and Stankiewicz et al (2013).…”

“…Although records from significant past earthquakes are sparse in Central Asia, we resorted to ground-motion simulations, following previous studies (e.g., Oth et al, 2010;Stankiewicz et al, 2013). In this work, the stochastic finite-fault simulation program EXSIM (Motazedian, 2005) has been used for generating synthetic ground-motion time series.…”

“…In this section, we provide an example of how efficient networks can be designed considering Bishkek as target, finding a balance in the trade-off problem of warnings being simultaneously as timely and accurate as possible. The process used for evaluating an existing or a hypothetical network is based on the one developed by Oth et al (2010). Using the synthetic ground-motion database from the event portfolio (see Scenarios Portfolio section), the effect of each scenario on the target city is considered in terms of the expected peak ground acceleration (PGA).…”

The Use of Spectral Content to Improve Earthquake Early Warning Systems in Central Asia: Case Study of Bishkek, Kyrgyzstan

“…Zollo et al (2009) first performed network evaluations and showed how improvements can be made. Oth et al (2010) developed a technique for designing optimal EEW systems, using an acceleration threshold based methodology as an example. The main attractiveness of this methodology lies in its simplicity, and its applicability to Central Asia has since been demonstrated (Stankiewicz et al, 2013;Pittore et al, 2014).…”