Simulations of the Storegga Tsunami on alternative bathymetric models

Steven J. Gibbons
NGI 2026/01/13

Description
-----------
Numerical tsunami simulations of the tsunami generated by Storegga slide on a range of candidate bathymetric models

Background
----------
Under https://doi.org/10.82554/sdl-56 we store a numerical simulation of the Storegga
slide in the Norwegian Sea (approximately 8150 BP) and multiple numerical simulations of the tsunami
that it caused, using the program Tsunami-HySEA and two different bathymetric models.
These models are the present day bathymetry as given in GEBCO (2024) and the paleobathymetry of
Clark et al. (2022a).

In the simulation dataset provided here, we parametrize a continuum of bathymetric models
between the present day topobathymetry and two different paleobathymetric models:
that of Clark et al. (2022a, 2022b) and that of Hill et al. (2014).

For both parametrizations, we have a parameter lambda that varies between zero and one such that

depth = paleo_depth * ( 1 – lambda ) + present_day_depth * lambda

and so, for lambda = 0, we have the paleobathymetry and, for lambda = 1, we have the present day
bathymetry.

There are four main folders:
Hill_lambda_simulations
Hill_lambda_bathymetry
and
Clark_lambda_simulations
Clark_lambda_bathymetry

Within the folders Hill_lambda_bathymetry and Clark_lambda_bathymetry
we have 11 files with lambda going from 0.0 to 1.0 in increments of 0.1, e.g.
Clark_lambda_bathymetry/Clark_GEBCO_lambda_0.300.nc
We also have the corresponding deformation file.

Within each of the folders Hill_lambda_simulations and Clark_lambda_simulations
is a separate folder for each value of lambda used, e.g.

Clark_lambda_simulations/Clark_GEBCO_lambda_0.300

contains all the input and output files for the simulation with the bathymetric model from Clark et al. e with
lambda = 0.3, such that the bathymetry is given by

depth = paleo_depth * 0.7 + present_day_depth * 0.3

THe file T-HySEA_v4.1.7_input.txt is the parameter file for the Tsunami-HySEA program
(version 4.1.7) and Clark_GEBCO_lambda_0.300_ts.nc contains the time-series information and
Clark_GEBCO_lambda_0.300.nc contains the spatial information (e.g. max_height).

When running the simulations, the files bathy.nc and deformation.nc must be present in the working directory.
These can either be copied from the files in the *_bathymetry folders or, better, linked using symbolic links.


References:

Clark, Chris D; Ely, Jeremy C; Fabel, Derek; Bradley, Sarah L (2022a):
  BRITICE-CHRONO maps and GIS data of the last British-Irish Ice Sheet 31 to 15 ka,
  including model reconstruction, geochronometric age spreadsheet,
  palaeotopographies and coastline positions [dataset].
  PANGAEA, https://doi.org/10.1594/PANGAEA.945729

Clark, C. D. et al. (2022b):
  Growth and retreat of the last British–Irish Ice Sheet, 31 000 to 15 000 years ago:
  The BRITICE‐CHRONO reconstruction. Boreas, 51(4), 699–758.
  https://doi.org/10.1111/bor.12594

GEBCO Bathymetric Compilation Group 2024. (2024):
  The GEBCO_2024 Grid—A continuous terrain model of the global oceans and land. (Version 1).
  NERC EDS British Oceanographic Data Centre NOC.
  https://doi.org/10.5285/1C44CE99-0A0D-5F4F-E063-7086ABC0EA0F

Hill, J., Collins, G. S., Avdis, A., Kramer, S. C., & Piggott, M. D. (2014):
  How does multiscale modelling and inclusion of realistic palaeobathymetry
  affect numerical simulation of the Storegga Slide tsunami? Ocean Modelling, 83, 11–25.
  https://doi.org/10.1016/j.ocemod.2014.08.007