Why do we need seismic hazards?
We are all well aware that with the ever-increasing energy consumption levels and the need for diversity of the energy sources, there is a trend of growing development in the energy sector. New build nuclear projects, renewable power plants, new hydrocarbon pipelines etc. are being build to meet the significant need for energy around the globe.
The development of such major projects however, depends on strict regulatory framework requiring thorough assessment of external to the installation hazards like geotechnical instabilities, extreme natural phenomena, man induced hazards etc.
One of the key external hazards which has always been an item of great emphasize is the vibratory motion caused by earthquakes. Licences of existing power sources have to be renewed and while new projects are planned, assessments of the seismic thread at the installation sites, hydrocarbon pipeline routes or other major infrastructure projects are likely to be needed.
Seismic hazard is an area which is evolving very rapidly in the scientific world with the globally expanded seismic instrumentation coverage ensuring high-quality records from micro, moderate and strong earthquakes. This evolution is so fast that it makes national and international seismic safety requirements obsolete by definition. To that end, most of the conventional building code seismic regionalizations around the world are developed either long time ago or defined within the framework of global projects that are sometimes ignorant to the local earth related databases and scientific knowledge.
Better than ever, we now understand the process of earthquake generation and this trend will improve with the increased geophysical, geotechnical and seismological datasets. It makes sense to reveal that our Planet Earth experienced exceptional earthquakes just within a decade from the start of the new millennium. The Mw 8.8 Chile event from 2010, the Mw 9.1 Tōhoku earthquake occurred in 2011 and the Sumatra Mw 9.2 from 2004, make the all times top 10 list for the most powerful earthquakes known to the human beings . This only in the last 15 years or so.
The risk is there. And lets face it - it shall not be underestimated. We would not disclose a secret saying that the scientifically acceptable ground motion level virtually anywhere today, would arguably incorporate different content compared to what national seismic maps prescribe. This is despite the emergence of several trans-continental seismic hazard models like SHARE and SERA, where the Seismic Source Characterization is postulated in a way, somewhat over-predicting the hazard and the associated seismic risk in the vicinity of major population centers because of the great interest imposed by the risk insurance industry.
Therefore, practical and sustainable path forward for states, investors and project owners is to get realistic seismic design bases for their new ventures in accord with the latest developments in the engineering practice.
We do that.