MArine Geo-hazards InduCed by underwater
LANDslides in the SW Iberian Margin
Submarine mass-failures (SMFs) constitute a widely recognized source of marine geo-hazards. They can compromise the safety and integrity of seafloor and subsurface infrastructures through destroying offshore installations or causing potential tsunamis. The importance of SMFs as contributors to marine geo-hazards has been recognized over the last 20-30 years, but they are seldom considered in the evaluation of quantitative offshore and coastal hazards.
MAGICLAND aims at developing quantitative assessment methods for SMFs-induced marine geo-hazards. To this end, past and possible future SMF episodes will be studied with unprecedented details through employing quantitative geomorphic, seismic, and geotechnical analyses. This will allow characterizing the size, distribution and rheology of SMFs that, coupled with numerical modelling, will lead to accurate prediction of the mass movement and the potential of SMFs to cause tsunami. Quantitative impact assessment of SMF flow on offshore structures and SMF-induced tsunami on coastal area will be then conducted through numerical modelling. The dissemination of the results is foreseen to contribute to the mitigation of the impact of SMF on future offshore installations and also to develop the awareness of the population for possible silent (non-seismic) tsunami events.
To achieve the objectives of the project, MAGICLAND adopts a rigorous work-plan, organized in six tasks:
Mapping submarine mass-failures in the SWIM
Leader: P. Terrinha (IPMA)
Objective: The main goal of this task is to establish the submarine mass failures (SMFs) history and to identify unstable areas liable to future SMFs, leading to the preparation of a unique SMFs-database in the region and therefore selecting the more favourable cases to be considered in the subsequent tasks.
T1.1: Inventory of documented SMFs in the SW Iberia Margin.
T1.2. Morphological analysis.
T1.3. Seismic reflection profiles interpretation.
T1.4: Generation of SMFs database.
1. Identify the past SMFs and unstable area liable to future events in the SWIM region.
2. Establish the typology and geometry of the identified SMF events.
3. Generate a GIS-database incorporating all the SMFs information.
Relationship with other tasks: This task will prepare the baseline information that will be used in all other tasks.
Geotechnical and physical properties of marine sediments
Leader: M. Quinta-Ferreira (UC)
Objective: This task aims at determining the physical and geotechnical properties of the sediments forming the slopes. Taking advantage of the availability of the cores from previous projects and expeditions that covered regions of distinct tectonosedimentary settings, a detailed analysis of the physical and geotechnical properties of sediments will be performed to pursue the objective of this task.
T2.1: Physical properties characterization.
T2.2: Determination of geotechnical properties.
T2.3: Update of SMFs database with the physical and geotechnical properties.
1. Determine physical and geotechnical properties of the slope sediments in the SWIM region.
2. Update SMFs GIS-database with the physical and geotechnical properties.
Relationship with other tasks: This task will quantitatively estimate physical and geotechnical properties of the slopes that are required for the modelling tasks (3 and 4)
Slope failure potential
Leader: C. Roque (IDL)
Objective: The main objective of this task is to perform the slope stability analysis on the areas liable to future SMF events and accordingly create a slope failure hazard map. To accomplish this goal, we propose to determine slope stability using a deterministic approach both in static and transient conditions.
T3.1: Slope stability analysis in static conditions.
T3.2: Slope stability analysis in transient conditions.
T3.3: Generation of slope failure hazard map.
1. Determine the failure condition of the slopes under static conditions.
2. Determine the failure condition of the slopes under transient conditions.
3. Generation of slope failure susceptibility map.
Relationship with other tasks: This task will establish the failure condition of the SMFs that will be considered in modelling the mass movement (Task 4) and the induced geo-hazards (Task 5).
Landslide rheology, mass movement and tsunamigenic potential
Leader: R. Omira (IPMA)
Objective: the goal of this task is to properly model of underwater landslide mass movement and its potential of tsunami generation considering rheological models that better represent the characteristics of the sediments involved and the typology of the landslide.
T4.1: Rheological models assignment for SMFs.
T4.2: Modelling SMFs Mass movement and potential of tsunami generation.
1. Define a rheological model for each identified SMF.
2. Develop a coupled mass movement-tsunami generation numerical code that considers all the possible SMF rheologies.
Relationship with other tasks: This task will model the SMFs mass movement and determine their potential of tsunami generation that will serve to quantify the induced marine geo-hazards (Task 5).
SMF-induced marine geo-hazards
Leader: R. Omira (IPMA)
Objective: the goal of this task is twofold: to evaluate the impact of the underwater mass movement on the seafloor infrastructures; and to develop a source-to-coast hazard model for the SMF-induced tsunamis in the SWIM region.
T5.1: Impact of SMFs on seafloor installations.
T5.2: SMF-induced tsunami impact on coast.
1. Quantify the impact of SMF mass movement on offshore installations.
2. Derive high-resolution tsunami hazard maps for mapped past- and future-SMFs.
3. Build the aggregate scenario as representation of the worst-case tsunami impact.
Relationship with other tasks: This task will use the mapped SMFs in tasks 1, the modelled mass movement and the computed initial tsunami conditions from task 4. Outcomes of this task will serve for the dissemination task 6.
Outreach and dissemination
Leader: M. A. Baptista (IDL)
Objective: The main goal of this task is to disseminate within the scientific community, the local authorities, and the public in general information on marine geo-hazards posed by submarine mass failures in the NE Atlantic region.
T6.1: Produce prototype hazard map.
T6.2: Produce educational material.
T6.3: Publication of scientific results.
T6.4: Creation of a project website.
1. Produce a prototype regional SMF-induced marine geo-hazards maps incorporating results from different tasks.
2. Produce educational posters.
3. Create a project website.
Relationship with other tasks: This task will use the output from all tasks.
2019 MAGICLAND Consortium
Project ID: PTDC/CTA-GEO/30381/2017
Project acronym: MAGICLAND
Project title: Marine geo-hazards induced by underwater landslides in the SW Iberian Margin
Starting date: 1 January 2019
Duration: 36 months
This project received funding from FCT