Seismically Induced Hazards in Balzers, Liechtenstein: Why Ancient Balzers was Safer Dr. Maria E. Brunhart-Lupo Dr. John Lupo Mr. Werner Brunhart

Dörrbecker, 2013

Balzers, Liechtenstein Town in southwestern Liechtenstein Area inhabited since the Hallstatt culture – Early Iron Age Town has been officially recognized since the early 800s The castle, Gutenberg, has been the center of town since the early to mid 1200s Total area of historic town was ~ 7 sq miles Total area of modern town is 7.6 sq miles

Seismic History Area is noted as seismically active for all of human history No record kept for Balzers, but kept for the Swiss side of the Rhine Valley Record shows earthquakes and associated hazards are known for the area from Roman times to modern Average is two earthquakes a day, usually under M2.0

Location of historic and modern Balzers

Seismic Hazards

Seismic Hazards Affecting Balzers Landslides Rockfall Avalanches Soil Liquefaction Floods Fires

Building Codes Within the past five years, particularly after a M5.4 hit the Rhine Valley in 2012, building codes have been rapidly updated All new buildings must be built to code, but older buildings are not subject to upgrade Need for updating of codes was raised due to the percentage of damage found in buildings constructed under ‘modern’ code Discrepancy lies in the relative lack of damage recorded in ‘historic’ structures

Damage Assessment 68% of modern buildings affected Under 10% of ‘historic’ (1800s or earlier) buildings affected Modern building damage = cracking in walls and foundations, broken glass, balcony detachments ‘Historic’ building damage = settlement of foundation footings, micro-cracking of exteriors

Construction Differences Modern codes versus older methods of construction Modern houses/resort housing versus farm houses Example of Gutenberg – 12 th century style construction

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