1. Page 1 SESSION 3 Land & Water Damage SPEAKERS: MARSHA BERGER (NYU) STEVE WARD (CSC) VASILY TITOV (NOAA) SOUHEIL EZZEDINE (LLNL) GALEN GISLER (LANL) JAY MELOSH (PURDUE) MICHAEL AFTOSMIS (ARC) RAPPORTEUR: DAVID MORRISON (ARC) [Date]

2. Page 2 SESSION 3 Land & Water Damage OVERVIEW: IMPACT EFFECTS, PRIMARILY FROM AIRBURSTS NEAR FIELD DAMAGE TSUNAMI GENERATION AND PROPAGATION [Date]

3. Page 3 SESSION 3 LOCAL OR REGIONAL EFFECTS (from Melosh) ATMOSPHERIC PASSAGE & AIRBURST Generates atmospheric heating and shock wave THERMAL RADIATION (FIREBALL) Starts fires SEISMIC SHAKING –Earthquakes EJECTA DEPOSTION Primarily local effect AIRBLAST –Shock waves from both airbursts and impacts TSUNAMI –The subject of the other papers in this session [Date]

4. Page 4 SESSION 3: Tsunami Impact tsunami are different from familiar seismic tsunami. Generally have short wavelength and travel less distance Impact tsunami can provide much more warning than seismic or landslide tsunami DART and other warning systems being established No matter how good the models are, need to understand that local conditions will greatly influence the tsunami, especially its propagation and run-up at shore. Need better modeling of formation for both impacts and airbursts. Need to account for water depth (deep ocean or continental shelf) Need to account for bathymetry Need to account for slopes at shoreline Need to understand distribution of coastal infrastructure and populations Van Dorn Effect? [Dat

5. Page 5 SESSION 3 What are the differences between tsunami formed by airbursts and ocean impacts? Ocean impacts heat and eject large quantities of water. These atmospheric effects should be taken into account. In both cases the atmospheric effects of the airburst needs to be considered. Ocean impacts deposit their energy deeper but create a smaller cavity. Initial wave is higher but it travels less far. Ocean airburst generates smaller cavity but wider. Wave height is smaller but the distance travelled is greater. For risk assessment, we need to know more about distribution of near-shore populations and infrastructure. An interagency collaboration to study the relative effects of airbursts over ocean and of impacts into the ocean would be valuable. In terms of overall impact risk, we still have major uncertainties about the risk associated with tsunami. [Date]

6. Page 6 Impact Hazard Revisited (Harris 2009)