Larger peak ground accelerations in extra-Carpathian area than in epicenter

<p>Devasting ― and, in some sense, unforeseen  ―  earthquakes in Nepal, Sumatra, Haiti, Japan  and elsewhere have triggered a heated debate about the legitimity and limitations of probabilistic seismic hazard  assessment(PSHA). The authors are coming with many recorded data which will open up a new challenge to seismologists studiing nonlinear site effects in 2-D and 3-D irregular geological structures, leading them to a realistic research subject in earth physics, in nonlinear seismology. Shortly, why are we recording PGA values much higher than epicenter value? There was a need to create, for Europe, a unified framework for seismic hazard assessment and to produce a common integrated European probabilistic seismic hazard assessment (PSHA) model and specific scenario based on modeling tools. The leading question is, if this is happening only in this area of Europe. Vrancea is the site of strong intermediate-depth seismicity, down to 160 – 200 km depth and large magnitudes (M<sub>W</sub> ≤ 7.9 - 8.0) and is one of the most active seismic zones in Europe. The latest strong and deep Vrancea earthquakes occurred on August 30, 1986 (Mw = 7.1; h = <strong>131.4 km</strong>, in epicenter a=162.60 cm.s<sup>2</sup> and at Chisinău:212 cm/s<sup>2</sup>;Focsani:310 cm/s<sup>2</sup>;Iaşi:181 cm/s<sup>2</sup>; Otopeni: 220cm/s<sup>2</sup> etc.); May 30, 1990 (Mw = 6.9; h = <strong>90.9</strong> km; in epicenter: 157 cm/s<sup>2</sup>; Chişinau:189 cm/s<sup>2</sup>; Oneşti:242 cm/s<sup>2</sup>;Periş:242 cm/s<sup>2</sup>; Bolintin din Vale:219 cm/s<sup>2</sup>; Campina;271 cm/s<sup>2</sup> etc. & May 31, 1990 (M<sub>W </sub>= 6.4; h = <strong>86.9</strong> km, in epicenter: a=102 cm/s<sup>2</sup>;Focşani:162 cm/s<sup>2</sup>.There are more than 200 values larger than epicenter ones. More, on October 28,2018 an earthquake (Mw=5.89 and h= <strong>147.8 km</strong> ) generate  acceleration of 8.65 cm/s<sup>2</sup> in epicenter Vrâncioaia and accelerations of   69 cm/s<sup>2</sup> in Ploieşti; 65  cm/s<sup>2</sup> in Leova - Republic of Moldova etc. Why in this part of Europe/World there are many peak ground accelerations recorded and are larger than epicenter values ?. Surface waves Rayleigh and Love waves ( A third type of surface wave, the Stonely wave propagates along an interface between two media and is more correctly an interface wave and are not dispersive, thus they decrease in amplitude with distance from the interface) are seismic waves which are guided along the surface of the earth and the layer near the surface and they do not penetrate into the deep interior.</p><p>On the other time, the Alpine Tethys was linked to the Euro-Asian back-arc basins located further east through the Moesia - Dobrogea Transform [G. G. Stampfli; http://sp.Lyellcollection.org/by guest on November 14, 2019]. It is observed along new times that in Dobrogea area the peak ground accelerations recorded in last time are smaller than epicenter ones and our Nuclear Power Plant is  safe  to strong Vrancea earthquakes. Peak ground accelerations recorded   in Muntenia, Moldova   and   Republic of   Moldova are maily larger than   Vrancioaia epicenter values (Gh.Mărmureanu, Certainties/uncertainties in hazard and seismic risk assessment of strong Vrancea earthquake. Romanian  Academy Press,2016,330 page,ISBN 978-973-27-2629-7).</p>

THE EMPIRICAL ANALYSIS OF SOIL LIQUEFACTION IN IMOGIRI SITE, YOGYAKARTA, INDONESIA

A strong earthquake with magnitude of 6.3 Mw, which was later known as the JogjaEarthquake, occurred in the southern part of Yogyakarta Special Province. The earthquakehad resulted in the huge damage to the buildings, public facilities as well as triggering theground failure phenomenon, which was known as liquefaction. An empirical analysis usingthe conventional method was performed to investigate the liquefaction severity for the siteinvestigation data in Imogiri, a site with the high-level of the liquefaction damage duringthe earthquake. The peak ground accelerations varied to 0.3 to 0.4g are also implemented inthe analysis. The results show that the investigated site is dominated by sandy soils. Thesandy soil in Imogiri site is categorised as the liquefiable layer during the Jogja Earthquakeand potentially to liquefy on shallow depth. In general, this study could warn the people forthe impact of soil liquefaction if the stronger earthquake happens in the future.

Telecom, Traffic Cones, and the Big One: Identifying Transportation and Communications Emergency Support Workforces and Calculating Their Exposure to Seismic Peak Ground Accelerations

Successful post-disaster response and recovery depends on prompt restoration of infrastructure, including transportation or communications. However, disasters can have an impact on the workforce responsible for restoration, for example, by damaging their homes. This study has two goals: 1. Identify workers potentially participating in restoring transportation and communications infrastructure; 2. Calculate these workers’ exposure to the peak ground accelerations (PGAs) of a 7.8 magnitude earthquake in a Southern California scenario, and compare it with the rest of the working population’s exposure. Four steps are required. First, calculate the mean PGA for each affected public use microdata area (PUMA). Second, identify the infrastructure restoration workforce by specifying Standard Occupational Classification (SOC) and North American Industry Classification System (NAICS) codes. When specifying, use the Emergency Support Function (ESF) Annexes for Transportation (ESF#1) and Communications (ESF#2) to clarify workers’ roles and responsibilities. This ESF-specific listing of codes is a novel contribution. Third, via frequency table, calculate the mean and standard deviation of transportation and communications workers’ exposure to PGAs in their PUMAs of residence. Finally, test the difference in mean PGA exposures between two populations: (a) transportation or communications workers and (b) the rest of the working population. This study finds that, for this scenario, transportation workers are exposed to statistically significant higher PGAs than non-transportation workers, and communication workers to significantly lower PGAs. For practitioners, knowing which worker categories a disaster disproportionately affects could justify pre-event investments in workforce preparedness and recovery planning efforts.

Performance of road bridges during the 14 November 2016 Kaikōura Earthquake

The transport infrastructure was majorly affected by the 14th November 2016 Kaikōura Earthquake. Severe vertical and horizontal peak ground accelerations generated high inertial forces, land-slides, and liquefaction. Most of the bridges in the Hurunui, Malborough and Kaikōura districts were critical nodes to the railway and road networks. In total, 904 road bridges across those districts were affected. Two reached the life safety limit state, suffering severe damage, however, most of the affected bridges experienced only minor to moderate damage. This paper describes the structural performance of the most severely damaged bridges based on observations made from site inspections. In addition to this, several performance issues have arisen from this event and are posed in this paper, hopefully to be addressed in the near future.