Estimation of Earthquake Early Warning Parameters for Eastern Gulf of Corinth and Western Attica Region (Greece). First Results

The main goal of an Earthquake Early Warning System (EEWS) is to alert before the arrival of damaging waves using the first seismic arrival as a proxy, thus becoming an important operational tool for real-time seismic risk management on a short timescale. EEWSs are based on the use of scaling relations between parameters measured on the initial portion of the seismic signal after the arrival of the first wave. To explore the plausibility of EEWSs around the Eastern Gulf of Corinth and Western Attica, amplitude and frequency-based parameters, such as peak displacement (Pd), the integral of squared velocity (IV 2) and the characteristic period (τc), were analyzed. All parameters were estimated directly from the initial 3 s, 4 s, and 5 s signal windows (tw) after the P arrival. While further study is required on the behavior of the proxy quantities, we propose that the IV 2 parameter and the peak amplitudes of the first seconds of the P waves present significant stability and introduce the possibility of a future on-site EEWS for areas affected by earthquakes located in the Eastern Gulf of Corinth and Western Attica. Parameters related to regional-based EEWS need to be further evaluated.

Benchmark NBC editions for seismic risk management of existing buildings in Canada

The National Research Council Canada recently developed a multi-criteria and multi-level framework for seismic risk management of existing buildings in Canada. One of the key criteria in this framework is benchmark NBC edition, which refers to the applicable edition of National Building Code of Canada (NBC) in which significantly improved seismic requirements were adopted and enforced. Since post-benchmark buildings are expected to demonstrate satisfactory seismic performance, they may be exempt from structural seismic risk assessment. This paper identifies benchmark NBC editions for 17 model building types in Canada. The identification starts by tracking major seismic improvements in the United States benchmark codes and standards. These improvements are then mapped to applicable NBC editions and relevant design standards. Provincial building code editions corresponding to benchmark NBC editions are also identified. The benchmark NBC editions and corresponding provincial building code editions help building owners quickly identify and exempt post-benchmark buildings with acceptable seismic risks and thus allocate resources to the buildings with potentially unacceptable seismic risks.

An integrated approach to seismic risk management in a moderate seismicity alpine region

<p>The Aosta Valley Region territory (Italian Western Alps) is affected by a moderate historical seismicity. Nevertheless, in the last fifty years, the growth of the population and infrastructures have significantly increased the overall seismic vulnerability.</p><p>More in detail, the most vulnerable targets (international highways and the largest inhabited areas including almost 90% of the resident population), are concentrated in a narrow area along the main Dora Baltea Valley.</p><p>Therefore, moderate earthquakes with return times of about 100 years, could have important impacts on the regional economy.</p><p>Furthermore it has to be considered that, in areas marked by moderate seismicity, where potentially damaging earthquakes have long return times, the local authorities in charge of civil protection do not always seem to have a clear perception and a strong historical memory of the seismic risk.</p><p>To improve the general resilience towards the earthquake hazards, the Regional geological survey of the Aosta Valley Region has undertaken a process aimed at realization of an integrated and organic seismic risk management, financed by the EU on INTERREG ALCOTRA RISVAL project – Operational program Italy - France (Alps - ALCOTRA) 2014-2020.</p><p>All the planned activities have been mainly aimed to improve the geological knowledge already available, in order to achieve a clearer framework of the potential active tectonic structures (faults and thrusts), mapping the distribution and the geophysical properties of the quaternary deposits, which could potentially amplify the seismic waves.  </p><p>More in detail, seismic microzonation studies have been extensively perfomed along the main regional road axes, including over 100 geophysical tests. At the same time, two detailed studies have been made: the first  one regarding the potentially active fault "Aosta-Col di Joux-Ranzola" (located along the Dora Baltea Valley), the second one assessing the correlation between recent instrumental seismicity and active tectonic structures on the Italian side of the Mont Blanc Massif.</p><p>In a final step, a regional inventory of the seismic "strategic" buildings (hospitals, fire stations, town halls, ecc.) has been implemented</p><p>All the data have been integrated in the regional web portal, where the main geological, geotechnical and geophysical data of the Aosta Valley are already available. The inclusion of knowledge and data in a single web platform, which can be consulted online, improves the expected phenomena knowledge and its potential impacts on the territory, with a positive impact on the land management strategies and allowing the prioritization of costly structural reinforcements of buildings and infrastructures. In addition, the activities have been also conceived to support the regional civil protection authorities in the earthquake emergency planning activity, identifying the safest paths  the rescue teams and the first infrastructures structures to be controlled after a seismic event.</p><p> </p>