Earthquake impacts are varied. They span from minor occurrences, perhaps causing a few examples of cracks within buildings, to devastating events that can almost annihilate extensive urban populations and effect national economies. The range of impacts and earthquake phenomena are of concern to a variety of professions including the insurer, the builder and earthquake engineer and the teams that plan the efficient use of urban land to mitigate against the worst effects of earthquake ground shaking. The Seismic Risk Group and the UEA seismological laboratory, affiliated through the Benfield Hazard Research Centre, can provide research led expertise and advice on the phenomena related to seismic hazards and risks including:

• data reviews and descriptive critiques
• earthquake geology field work
• earthquake and crustal deformation monitoring
• numerate analyses of seismic hazard, vulnerability and earthquake risk
• engineering seismological analyses of earthquake strong motion data and engineered structures
• loss modelling and decision analysis
• post-earthquake management and long term reconstruction including non-engineered buildings in seismic areas
• risk perception

Knowledge and understanding of local seismicity depends largely on the extent and duration of local study. In the global context Europe has substantial seismicity (see global map) and extensive studies of devastating historical earthquakes - the Lisbon, Portugal earthquake of 1755 provides a graphic illustration. This earthquake and the subsequent 30 m tsunami caused ~60,000 deaths and heavily damaged 15-20,000 buildings.

Seismic hazards can be low and rare or high and relatively frequent, the consequences usually being losses to buildings and infrastructure, insured or otherwise, and fatalities. In Turkey, the August 1999 earthquake was followed by both tsunami and highly damaging industrial fires. This earthquake was both heavily damaging in itself and raises fears for the capital city of Istanbul. Seismic hazards can be quantified statistically by a variety of methods and earthquake recurrence statistics provide vital information.

Estimation of risk and expected losses in future scenario earthquakes requires knowledge of building stock in an urban area and building vulnerability to earthquake ground shaking, again a vital area of study.

Mitigation against such losses involves the engineer in understanding of building response and selection of appropriate strong motion records. A combination of soil-foundation conditions and building response to shaking caused by the Mexico City earthquake in 1985 selectively destroyed many modern medium rise buildings. Decisions on detailed land use require understanding of geotechnical properties and the potential for soil amplification of earthquake vibration.

In situ studies can now span Geographic Information Systems rendering of data in a uniform environment through to Global Positioning Systems observation of crustal deformations and movements in the vicinity of large engineering projects, or purely as investigations of geodynamics to further our understanding.

However, in some communities even simple remedies like timber ring beams can provide protection. Both engineered and non-engineered building construction can form a part of post-earthquake management and long term reconstruction. Inter-dependencies in earthquake phenomena are broad and Decision Trees aid cost benefit analysis of complex earthquake risk situations.