ASTARTE test site Lyngen Carl B. Harbitz NGI ASTARTE WP9 Meeting Paris, 23-24 January 2014 Lyngen test site, northern Norway • Potential rockslide from the mountain Nordnes, 7 km from the village Lyngseidet • Volume estimate up to 22 Mm3 with 11 Mm3 as the most likely upper limit 1810 Rock slide tsunami from Pollfjellet Mountain Among the largest rock slides in Norway 2 km wide head scar, 20 km south of Nordnes Waves observed more than 20 km away in both directions 3 large waves 2 m high waves in the head of the fjord 14 perished, large damages Today: Road tunnel to protect snow avalanches and rockfalls Submarine landslide tsunami sources (1) • At least 6 very large landslides have occurred in the Norwegian and Greenland Basins during the last ~20ka, giving a frequency of 1 in ~3-to-4000 years • The 8200 BP Storegga Slide produced a far field tsunami • This project will consider tsunamis generated at 3 different locations within the Norwegian and Greenland Basins to capture the effects of variable source location Submarine landslide tsunami sources (2) • Modelling will consider a range of landslide motions, including how multi-stage failure affects tsunami generation • Slide motion will be informed by field studies of the Trænadjupet Slide, which is the last major slide at ~4 ka. • This work will extend from a £2.3 Million UK (NERC) funded research project, which includes a 1 month research cruise to map and date the Trænadjupet Slide in summer 2014 What has already been done by NGI? • 3 reports on rockslide tsunamis in Lyngen • 2008, 2010, 2013 • Updated volume estimates • Refined inundation modelling • NGI’s results are the official ones used by the local authorities for evacuation and land-use planning, etc. Description of the rockslide Detailed geological surveying for slope stability analysis «1a» ~ 7 Mm3 «2» ~ 11 Mm3 Bathymetry, rockslide location • Areas 1-31 for detailed inundation studies Nordnes rock slope Official results Used for evacuation and land-use planning, etc. (in pipeline) Runup Arrival Location Name Min [m] Max [m] [minutter] 1 Koppangen 2 7 5 2 Årøybukt 2 14 3 3 Elvejorda 5 36 2 4 Lyngseidet 6 33 2 5 Karnes 4 3 6 Kjeldnes 4 19 3 7 Pollneset 4 21 3 8 Lyngspollen 3 7 8 9 Furuflaten 4 11 7 10 Rasteby 3 8 8 11 Elvenes 2 6 10 12 Elvevollen 2 7 15 13 Oteren 2 6 24 14 Horsnes-Elsnes 3 6 13 15 Skibotn 3 10 9 16 Forraneset 3 15 5 17 Brattvoll 11 31 2 18 Indre-Nordnes 19 46 <1 19 Nordnesodden 14 46 <1 20 Manndalen 3 11 5 21 Skarvdalen 3 3 7 22 Birtavarre 3 6 12 23 Trollvik 3 4 8 24 Langneset-Strand 3 5 6 25 Strand 5 13 4 26 Olderdalen 6 17 3 27 Nordmannvik 3 17 4 28 Strandli-Engeneset 3 8 5 29 Djupvik 3 5 6 30 Spakenes 2 5 8 31 Hamnes 2 5 13 Vulnerability and risk • The Lyngen test site consists of several villages along the fjord based on fishery and local industry • Total population 6000 • The ferries and the boats on the fjord, together with the road running along the shoreline, are the only alternatives for transport and travelling in the region • The area is much visited by tourists Mitigation • Rockslope monitoring • Lasers, crackmeters, tiltmeters, rod extensometers, GPS network, instrumented boreholes • TWS system based on the monitoring • Operational cell phone warning; location and address • 72 hours warning! • Initial land-use and evacuation planning for rockslide tsunamis in Lyngen is now performed by the ASTARTE end-users Troms County, the local municipalities, and the preparedness centre NordNorsk FjellOvervåking (NNFO) http://www.nnfo.no/ • Much based on studies of rockslide tsunamis by NGI • 2013 Barents Rescue international emergency exercise Available data for analysis of tsunami hazard, vulnerability and resilience, risk • Bathymetry (resolution 25 m) • Topography (1 m contours in most areas) • Rockslide scenarios • Location, volume, configuration, monitoring data/movements, dynamics • Literature and data on the submarine landslides (+NERC) • Detailed modelling of tsunami inundation scenarios • Data on population, infrastructure, critical facilities, land use, ecosystems, tourism, etc. • Experience from exercise • Some data are restricted Lyngen test site interaction with other ASTARTE WPs • WP2: Tsunami source areas and likelihood • WP3: Tsunami «source design» • WP5: Tsunami impact on coastal structures • WP7: Norwegian fjords as a laboratory for short-time TWS? • WP8: Tsunami hazard and risk analysis • Applications of methods • WP9: Tsunami resilience analysis The EU FP7 CONCERT-Japan RAPSODI project: Risk Assessment and design of Prevention Structures fOr enhanced tsunami DIsaster resilience (2013-2015) 1. Establish a new method for quantitative tsunami risk assessment 2. Design of novel mitigation measures 3. Cooperation and exchange of knowledge Partners: NGI, Norway – PARI, Japan – METU, Turkey – TU-BS, Germany http://www.ngi.no/en/Project-pages/RAPSODI/ Relevant synergies for ASTARTE tasks 9.6 (prevention structures) and 9.7 (guidelines) !? Why Lyngen? • A real threat exists! The situation is considered hazardous • Combination of sources • Rockslides and submarine landslides • Special challenges related to complex fjord geometries • Much work already performed • Slope stability and tsunami analyses, monitoring, operational TWS, evacuation and land-use planning, rescue exercises Much data • Norwegian fjords as a laboratory for short-time TWS • Attractive, but don’t forget the climate (70o N) • Our kind request: All work should be planned jointly with the end-user • Ensure usefulness and consistency • Avoid confusion and fear • Joint workshop for “Lyngen partners” Thank you What has already been done by NGI? • 2008: NGI report 20071677-1, run-up based on amplification factors. Volumes 7 og 11 Mm3 • 2010: NGI report 20100617-00-1-R, suggesting areas to be included for refined run-up modelling. Volume 22Mm3. • 2013: NGI report 20130206-01-R, hazard zoning by using run-up model («MOST»). • NGI’s results are the official ones. • The set of numerical models at NGI were improved during the last ten years (generation, propagation and run-up).