Carl Bonnevie Harbitz

Norwegian Geotechnical Institute | NGI · Department of Natural Hazards

In this study we investigate the effect of prior seismic shaking on the monotonic shear strength of saturated Ottawa Sand 20/30. We perform a series of stress-controlled undrained cyclic triaxial tests with different seismic intensities intentionally without causing failure, followed by drainage of the excess pore pressure and an undrained monotoni...

Landslides are the second most frequent tsunami source worldwide. However, their complex and diverse nature of origin combined with their infrequent event records make prognostic modelling challenging. In this paper, we present a probabilistic framework for analysing uncertainties emerging from the landslide source process. This probabilistic frame...

Sediment slumps are known to have generated important tsunamis such as the 1998 Papua New Guinea (PNG) and the 1929 Grand Banks events. Tsunami modellers commonly use solid blocks with short run-out distances to simulate these slumps. While such methods have the obvious advantage of being simple to use, they offer little or no insight into physical...

Tsunamis are natural hazards that can be caused by submarine landslides. Landslides with short run-out and duration are called slumps, and their tsunami generation have commonly been modelled simplistically by using blocks. The block approach was used for modelling tsunamis of important historical events such as the 1998 Papua New Guinea (PNG) and...

Submarine landslides have been identified in almost all ocean basins worldwide. The largest submarine landslides occur on very shallow slopes and can be far larger than any terrestrial landslide. Submarine landslides can produce tsunami whose far‐reaching effects can rival those produced by earthquake‐tsunamis and threaten increasingly populated co...

In the present study, we analyse the influence of submarine slump source dynamics on tsunami generation. Slump induced tsunamis have traditionally been treated using block sources with prescribed velocities as tsunami sources, such as for describing the tsunami generation due to important historical events like the 1998 Papua New Guinea and the 192...

On 18 November 1929, an M w 7.2 earthquake occurred south of Newfoundland, displacing >100 km ³ of sediment volume that evolved into a turbidity current. The resulting tsunami was recorded across the Atlantic and caused fatalities in Newfoundland. This tsunami is attributed to sediment mass failure because no seafloor displacement due to the earthq...

This paper presents selected results of the interdisciplinary research project Impacts of extreme weather events on infrastructure in Norway (InfraRisk) carried out between 2010 to 2013, as part of the program NORKLIMA (2004 2013) of the Research Council of Norway (RCN). The project has systematized large amounts of existing data and generated new...

Applying probabilistic methods to infrequent but devastating natural events is intrinsically challenging. For tsunami analyses, a suite of geophysical assessments should be in principle evaluated because of the different causes generating tsunamis (earthquakes, landslides, volcanic activity, meteorological events, asteroid impacts) with varying mea...

A large rockslide was released from the inner Askja caldera into Lake Askja, Iceland on 21 July 2014. Upon entering the lake it caused a large tsunami that traveled about ∼3 km across the lake and inundated the shore with vertical run-up measuring up to 60–80 m. Following the event, comprehensive field data were collected, including GPS measurement...

Large tsunamis occur infrequently but have the capacity to cause enormous numbers of casualties, damage to the built environment and critical infrastructure, and economic losses. A sound understanding of tsunami hazard is required to underpin management of these risks, and while tsunami hazard assessments are typically conducted at regional or loca...

A coastal landslide occurred at Statland, Namdalseid county, mid-Norway, on January 29, 2014, and generated a local tsunami. Neither the landslide nor the tsunami resulted in severe casualties, but the landslide tsunami gave rise to a maximum run-up height of 10 m and caused local damage to the Statland village. The limited size of the landslide as...

The 2011 Tōhoku event showed the massive destruction potential of tsunamis. The Euro-Japan “Risk assessment and design of prevention structures for enhanced tsunami disaster resilience (RAPSODI)” project aimed at using data from the event to evaluate tsunami mitigation strategies and to validate a framework for a quantitative tsunami mortality risk...

This chapter introduces a comparison between two methods for estimating the risk of a tsunamigenic rockslide at Åknes, Norway. The first method follows a classical approach based on best estimates of the risk factors (i.e., hazard, vulnerability, and elements at risk). The second method follows a more recent approach based on Bayesian networks, whi...

Coastal inundation due to multiple hazards was analysed for a potential manufacturing plant at the Batu Kawan Industrial Park in Penang state, Malaysia. The analysis accounted for river floods, rainfall and flash floods, cyclones, tides, storm surges, sea-level rise, and tsunamis. Earthquakes, volcanoes, and the effects of climate changes were also...

Clay-rich landslides commonly involve retrogressive mass and momentum release mechanisms. Motivated by the retrogressive behaviour of major landslides offshore Norway, previous studies have demonstrated substantial effects of the release rate on the generation of the tsunami. However, the few existing models are limited to overly idealized conditio...

This report focuses on large scale accessibility mapping and evacuation simulations of the ASTARTE test sites. It presents the main results achieved in the Task 9.4 of the WP9. The aim of this task is to provide operatives with scenario-based tools and solutions to develop evacuation plans for local communities. The hazard scenarios were based on t...

This review presents modelling techniques and processes that govern landslide tsunami generation, with emphasis on tsunamis induced by fully submerged landslides. The analysis focuses on a set of representative examples in simplified geometries demonstrating the main kinematic landslide parameters influencing initial tsunami amplitudes and waveleng...

A number of examples are presented to substantiate that submarine landslides have occurred along most continental margins and along several volcano flanks. Their properties of importance for tsunami generation (i.e. physical dimensions, acceleration, maximum velocity, mass discharge, and travel distance) can all gain extreme values compared to thei...

An unstable rock volume of more than 50 million m³ has been detected in the Åkerneset rock slope in the narrow fjord, Storfjorden, Møre & Romsdal County, Western Norway. If large portions of the volume are released as a whole, the rockslide will generate a tsunami that may be devastating to several settlements and numerous visiting tourists along t...

Tsunamis are infrequent events with the power to cause massive loss of life, large economic losses, and cascading effects such as destruction of critical facilities. Historical tsunamis and paleotsunami evidence indicates indirectly that massive megathrust earthquakes leads to the majority of the losses due to tsunamis. There is a need to quantify...

The 2004 Indian Ocean tsunami had a significant impact on the Tamil Nadu coast in India. In this paper, a range of field survey data collected by different survey teams available in literature have been analyzed and compiled to serve as a basis for validation of numerical tsunami simulations. The individual field surveys reveal a significant scatte...

The BIG’95 landslide was emplaced 11,500 years ago and is one of the largest known submarine landslides in the Mediterranean Sea. The simulated landslide dynamics matches the observed run-out and deposited thickness. Water elevation simulated by using a dispersive tsunami model exceed 10 m close to the landslide area and at the nearest shorelines....

This article focuses on the effect of dispersion in the field of tsunami modeling. Frequency dispersion in the linear long-wave limit is first briefly discussed from a theoretical point of view. A single parameter, denoted as "dispersion time", for the integrated effect of frequency dispersion is identified. This parameter depends on the wavelength...

The threats posed by submarine landslides to human civilization are the disappearance of valuable land near the shoreline, the destruction of seafloor installations like cables, pipelines or oil wells, and - most importantly - the devastation of coastal areas by landslide-generated tsunamis. Assessing and mitigating these hazards almost invariably...

The 1978 landslide at Rissa is the largest to have struck Norway during the last century and is world-famous because it was filmed. Swath bathymetry data and seismic reflection profiles reveal detailed information about the subaqueous morphology of the mass-transport deposits (MTD). Results show that the landslide affected nearly 20% of the lake fl...

Eastern Indonesia and the southern Philippines comprise a huge and seismically highly active region that has received less than the deserved attention in tsunami research compared with the surrounding areas exposed to the major subduction zones. In an effort to redress the balance the tsunami hazard in this region is studied by establishing a tsuna...

The present study documents a high tsunami hazard in the Caribbean region, with several thousands of lives lost in tsunamis and associated earthquakes since the XIXth century. Since then, the coastal population of the Caribbean and the Central West Atlantic region has grown significantly and is still growing. Understanding this hazard is therefore...

Most tsunami modelers rely on the shallow water equations for predictions of propagation and runup, either by using one of the standard codes or by means of an in-house code. Some groups, on the other hand, insist on applying dispersive wave models, sometimes even with enhanced nonlinear properties. Dispersive models are also available as standard...

On 11 March 2011 the Tohoku tsunami devastated the east coast of Japan, claiming thousands of casualties and destroying coastal settlements and infrastructure. In this paper tsunami generation, propagation, and inundation are modeled to hindcast the event. Earthquake source models with heterogeneous slips are developed in order to match tsunami obs...

Most tsunami models apply dislocation models that assume uniform slip over the entire fault plane, followed by standard analytical models based on Volterra’s theory of elastic dislocations for the seabed deformation. In contrast, we quantify tsunami runup variability for an earthquake with fixed magnitude but with heterogeneous rupture distribution...

The transport and deposition of sand in deepwater submarine environments has traditionally been linked mainly to dilute sediment gravity flows of turbulent character, generally referred to as turbidity currents. Based on laboratory investigations of sand-rich experimental flume flows, we analyze an alternative mechanism for transport and deposition...

This study presents simulations of earthquake tsunami propagation and inundation towards the Indian coastlines, more specifically towards the town of Nagapattinam in the Tamil Nadu region. The MIKE 21 Flow model as well as a combination the dispersive GloBouss model and the ComMIT model are employed, and a model comparison is provided. The study in...

The 1888 landslide and tsunami along the shore of the bay of Trondheim, central Norway, killed one person and caused major damage to port facilities. Recent bathymetric surveys, high-resolution seismic profiles and CPTU piezocone tests provide detail information about the morphology of the seafloor and landslide mechanisms, which can be used in tsu...

This paper introduces the application of a simple and practical method for estimating the risk associated with a potential tsunamigenic rockslide, by assessing quantitatively hazard, vulnerability, and elements at risk. The proposed method introduces empirical relations between the risk components and illustrates the uncertainty propagation through...

On September 29th, 2009 at 6:48 AM local time, a series of earthquakes generated near the Tonga trench (15.509°S, 172.034°W) triggered a tsunami that reached the shores of Tonga, the Independent State of Samoa, and American Samoa. Effects of the tsunami were seen on several other Pacific islands. Devastation was widespread, resulting in 9 fatalitie...

Much remains to understand the dynamic processes during the flow of submarine landslides. A first relevant problem is to explain the extraordinary mobility of submarine landslides, which has no comparison in subaerial mass movement. Another challenging question is the apparent disparity between submarine landslides that remain compact for hundreds...

Most tsunami models apply standard earthquake dislocation models that assume uniform slip over the entire fault plane. The purpose of this study is to cover a wide range of possible fault ruptures for one seismic magnitude and study how it influences the run-up distribution. Several authors have raised this issue, but a broader study on the stochas...

A major unstable rock volume has been detected in the mountain side, Åkneset, in the narrow fjord, Sunnylvsfjorden, Western Norway. If large parts of the unstable masses are released as a whole, the slide will generate a tsunami that may be devastating to several settlements along the fjord. The maximum volume of moving masses may be over 80 Mm3. T...

In the aftermath of the 2004 Indian Ocean tsunami, a large increase in the activity of tsunami hazard and risk mapping is observed. Most of these studies are limited to site specific studies with detailed modelling of the run-up locally. However, fewer studies on the regional and global scale exist. Therefore, tsunamis have been omitted previous co...

Funded by the Norwegian Government, NGI and the University of the West Indies (UWI) with support from the Coastal Zone Management Unit Barbados (CZMU) have completed a two years capacity building program on natural disasters mitigation in the Caribbean, where the following is undertaken: i) preparation of regional tsunami hazard and exposure maps t...

Tsunami hazard assessment from earthquakes along the western Hellenic Arc as well as from simulation of paleo-submarine landslides in the Ebro Margin (BIG'95) are presented within the framework of the EU project TRANSFER (Tsunami Risk and Strategies for the European Region). Modelling of the tsunami propagation using a dispersive model, nested with...

Potential tsunamigenic sources in the NE Atlantic are studied for a regional tsunami hazard assessment within the framework of the EU project TRANSFER (Tsunami Risk and Strategies for the European Region). Both near-field and far-field sources are considered. Potential rockslides located in the fjords in Western Norway are the only high risk tsunam...

The 2004 Indian Ocean Tsunami has led to an increased awareness of tsunamis on a global level, and in particular in the South East Asian region. Emphasis has been on awareness as well as establishing warning system, and to a less degree on tsunami hazard and risk mapping. Notwithstanding, there is a need for quantifying the hazard and risk on a reg...

An evaluation of rock slide tsunami hazard is applied to all Norwegian lakes larger than 0.1 km2 based on their topographical setting. The analysis results in a topographic rock slide potential score that indicates the relative hazard in each lake. Even though the score value each lake receives should be interpreted with caution, the distribution o...

This review presents a compilation of swath bathymetry data (16500 km2 coverage) of a massive landslide on the northern Svalbard margin. The Hinlopen-Yermak landslide has its main escarpments (maximum 1500 m high) at the mouth of the Hinlopen cross-shelf trough. The landslide, dated ~30 ka, is a multi-phase margin collapse that likely developed ret...

This book represents a capitalisation of knowledge from previous EC research projects in the field of Natural hazards and, in particular, the CADZIE and SATSIE projects addressing the problem of avalanches. It is about the design of dams and other protection measures in the run-out zones of wet- and dry-snow avalanches. The book summarises recent t...

Recent experimental and theoretical studies of the flow of avalanches against obstructions have been used, in combination with traditional design guidelines, to formulate recommendations for the design of dams and other protection measures in the run-out zones of wet- and dry-snow avalanches. These recommendations deal with the design height of dam...

Multibeam bathymetry and seismic data disclose three submarine slides in the outer Boknafjord area, SW Norway. The largest slide (Arsneset slide) has a volume of ca. 28 × 106 m3. The scar of this slide is 15–30 m high and it covers an area of ca. 1.4 × 106 m2. Seismic data on sediment thicknesses and sedimentation rate estimates from radiocarbon da...

The 17 July 2006 magnitude Mw 7.8 earthquake off the south coast of western Java, Indonesia, generated a tsunami that effected over 300 km of coastline and killed more than 600 people, with locally focused runup heights exceeding 20 m. This slow earthquake was hardly felt on Java, and wind waves breaking masked any preceding withdrawal of the water...

The wave characteristics and hazards related to tsunamis generated by submarine landslides and earthquakes are discussed. Example simulations of the 8100 BP Storegga Slide tsunami, the probable pre-Last Glacial Maximum Hinlopen Slide, potential North Sea Fan and La Palma scenarios, the 1998 Papua New Guinea tsunami, and the 2004 Indian Ocean tsunam...

One of the largest Holocene landslide mapped on Earth is the Storegga Slide offshore Norway. Between 2500 and 3400 km3 material were mobilized in a retrogressive process, generating a huge tsunami dated to about 7300 14C years BP, or ca 8100 calendar years BP. The tsunami is documented from onshore deposits along the entire Norwegian coast, on the...

The Monday, July 17, 2006 Central Javan 7.7 earthquake triggered a substantial tsunami that killed 600 people along a 200km stretch of coastline. The earthquake was not reported felt along the coastline. While there was a warning issued by the PTWC, it did not trigger an evacuation warning (Synolakis, 2006). The Indian Ocean Tsunami Warning System...

The primary background for the present study was a project to assist the authorities in Thailand with development of plans for how to deal with the future tsunami risk in both short and long term perspectives, in the wake of the devastating 26 December 2004 Sumatra-Andaman earthquake and tsunami. The study is focussed on defining and analyzing a nu...

Huge landslides, mobilizing hundreds to thousands of km(3) of sediment and rock are ubiquitous in submarine settings ranging from the steepest volcanic island slopes to the gentlest muddy slopes of submarine deltas. Here, we summarize current knowledge of such landslides and the problems of assessing their hazard potential. The major hazards relate...

Huge landslides, mobilizing hundreds to thousands of km3 of sediment and rock are ubiquitous in submarine settings ranging from the steepest volcanic island slopes to the gentlest muddy slopes of submarine deltas. Here, we summarize current knowledge of such landslides and the problems of assessing their hazard potential. The major hazards related...

Submarine mass wasting in the form of glacial mudflows, river-laden debris flows, rock avalanches, sandy debris flows, outrunner blocks, or turbidity currents, reveal an extraordinary mobility, demonstrated by the very long runout distance between the source area and the final deposit, even on very gentle gradients. Laboratory experiments reveal th...

The characteristics of a tsunami generated by a submarine landslide are mainly determined by the volume, the initial acceleration, the maximum velocity, and the possible retrogressive behaviour of the landslide. The influence of these features as well as water depth and distance from shore are discussed. Submarine landslides are often clearly sub-c...

This work presents numerical simulations of the tsunami generated by the Dec. 26, 2004, Sumatra-Andaman earthquake. The numerical models employed include the linear shallow water equations, a weakly nonlinear and dispersive model (Boussinesq equations), and ray theory for linear hydrostatic waves. Four different tsunami sources, constructed from in...

On December 26 2004 an earthquake, of magnitude 9.3 on the Richter scale and with an epicentre off the NW tip of Sumatra, occurred. In an area covering 300 km by 1200 km the earthquake caused up to approximately 3 meter vertical displacement of the seabed. This movement generated a massive tsunami wave that according to the World Health Organisatio...

Twelve well-documented dry-snow avalanches from the instrumented Ryggfonn path in western Norway were selected for back-calculations with several dynamical avalanche models. In each case, the run-out distance, the front velocity in the lower track, the extent of the deposits and the depth profile along a line are known. A 16m high and 100m wide ret...

Recent experimental and theoretical work on the dynamics of submarine debris flows is summarized. Hydroplaning was first discovered in laboratory flows and later shown to likely occur in natural debris flows as well. It is a prime mechanism for explaining the extremely long runout distances observed in some natural debris flows even of over-consoli...

Tsunami generation by submarine slides have been a major concern in the risk assessment for the Ormen Lange gas field off Western Norway. Tsunamis are analysed with a numerical model supplemented by an analytical one. Both models show how slide extensions and slide dynamics influence the tsunamigenic potential for a large region. Several combinatio...

Deposits from the Storegga tsunami have been found in coastal areas around the Norwegian Sea and North Sea, from the northeast coast of England to beyond the Arctic Circle in northern Norway. The tsunami deposits reach onshore elevations of 10–12 m above sea level of their time in western Norway, 3–6 m in northeast Scotland and above 20 m on the Sh...

The Storegga slide, released about 8200 years ago off the western coast of Norway, is a complex system of debris flows which occurred on the remains of previous Pleistocenic slides materials. Following geological mapping and interpretation of data gathered with geological and geophysical methods, the Storegga slide has been interpreted as consistin...

Tsunami generation from submarine gravity mass flows is investigated using linear two-dimensional analytical models, a simplified slide geometry, and a prescribed sub-critical slide velocity. Slide characteristics as maximum slide velocity, initial acceleration, slide length, and thickness, are all found to determine the characteristics of the tsun...

There is an urgent need to Improve the basic understanding of geohazards and our ability to deal with the risks associated with them. The International Centre for Geohazards (ICG) does research on the assessment, prevention and mitigation of geohazards, offshore as well as on land. The main focus is placed on landslides and their effects, such as t...

Large rock-slope failures are common events in the inner fjord areas of western Norway. Rock avalanches and related tsunamis have caused serious disasters, and during the last 100 years more than 170 people have lost their lives in western Norway. The first stage in the hazard evaluation has been the registra- tion of historical events and mapping...

In this paper, slides and debris flows in overconsolidated clay materials are simulated numerically. As a case study, the models are applied to the Storegga slide in the Norwegian Sea and in particular to the sub-region called Ormen Lange, where the information available is the most precise for a subaqueous debris flow. Three different models for t...

A set of laboratory experiments on subaqueous debris flows is reported where total stress as well as pore pressure transducers were mounted in the bed. Sediment texture ranging from clayey (viscoplastic) to sandy (granular) were used in the experiments, in order to investigate changes in pressure evolution. The pressure readings confirm earlier stu...

Numerous field cases illustrate the puzzling tendency of subaqueous debris flows to flow with much less resistance than their subaerial counterparts under otherwise comparable conditions. Subaqueous debris flows may attain stupefying runout distances of hundreds of kilometers, even on very gentle slopes. In order to understand the role played by wa...

1] Examination of submarine clastic deposits along the continental margins reveals the remnants of holocenic or older debris flows with run-out distances up to hundreds of kilometers. Laboratory experiments on subaqueous debris flows, where typically one tenth of a cubic meter of material is dropped down a flume, also show high velocities and long...

1] Subaqueous debris flows often attain significantly higher velocities and longer run-out distances than their subaerial counterparts in spite of increased viscous drag and reduced effective gravity due to buoyancy. Recent experimental research suggests that a basal lubricating layer of water associated with hydroplaning decouples the sediments fr...

The Storegga slide is one of the largest submarine slides in the world, and occurred about 8000 calendar years BP. Evidence of a tsunami generated by this slide event have been found along the coast of Norway, Scotland and the Faeroe Islands. Based on the reconstructed bathymetry of the sediments before slide release, the Storegga slide tsunami has...

A huge slide (volume of 2400 km3 and run-out 450 km) was released in the Storegga area off the western coast of Norway during early Holocene, followed by numerous smaller debris flows. We perform numerical simulations of the giant slide using a Bingham model for the clay material. Agreement with present deposit distribution and run-out is found by...

The EU programme CADZIE (Catastrophic Avalanches: Defence Structures and Zoning in Europe), was established after the catastrophic 1999 avalanche winter in Europe. The overall objective of the programme is improved snow avalanche risk management by: (1) improved avalanche hazard zoning by computational models; and (2) improved understanding of the...

Seismic images and sediment core data from the Bear Island and Isfjorden fans localized along the Svalbard–Barents Sea continental margin, reveal an interesting depositional system consisting of stacked debris flow lobes. The frequent release of debris flows was associated with large volumes of sediment rapidly delivered to the shelf break during p...

The EU program CADZIE (Catastrophic Avalanches, Defence Structures and Zoning in Europe), was established after the catastrophic 1999 avalanche winter in Europe. One objective of the program is improved avalanche hazard zoning. One contribution to meet the needs is a proposal for improved estimation of snow avalanche and rock fall risks on roads an...

Submarine slides and debris flows are common and effective mechanisms of sediment transfer from continental shelves to deeper parts of ocean basins. They are particularly common along glaciated margins that have experienced high sediment flux to the shelf break during and after glacial maxima. During one single events typically lasting for a few ho...

Tsunamis generated by rockslides represent one of the most serious natural hazards in Norway, exemplified by the 1934 Tafjord catastrophy where 2-3 mill. cubic m of rocks dropped into the fjord. The wave generated by the slide reached a maximum run-up height of 62 m above seal level and 40 people were killed. Four historical and potential future ts...

The reduced societal acceptance of living in regions exposed to snow avalanches, and the increased economic consequences when houses are located within a hazard zone, highlight the uncertainty concerning avalanche run-out prediction. The limitations of today's zoning procedures are especially pronounced in potential avalanche terrain where there ar...

Slope stability is evaluated at two locations on high latitude, deep sea fans along the Svalbard–Barents Sea margin, based on available samples and using an “infinite slope” analysis. The stability evaluation uses the Mohr–Coulomb failure criterion, and a semi-analytical approach based on Gibson's formulation for determining the excess pore pressur...