Title
Development of a seismic site-response zonation map for the Netherlands
Author
van Ginkel, J.
Ruigrok, E.
Stafleu, J.
Herber, R.
Publication year
2022
Abstract
Earthquake site response is an essential part of seismic hazard assessment, especially in densely populated areas. The shallow geology of the Netherlands consists of a very heterogeneous soft sediment cover, which has a strong effect on the amplitude of ground shaking. Even though the Netherlands is a low- to moderate-seismicity area, the seis mic risk cannot be neglected, in particular, because shallow induced earthquakes occur. The aim of this study is to estab lish a nationwide site-response zonation by combining 3D lithostratigraphic models and earthquake and ambient vibra tion recordings. As a first step, we constrain the parameters (velocity con trast and shear-wave velocity) that are indicative of ground motion amplification in the Groningen area. For this, we compare ambient vibration and earthquake recordings us ing the horizontal-to-vertical spectral ratio (HVSR) method, borehole empirical transfer functions (ETFs), and amplifica tion factors (AFs). This enables us to define an empirical re lationship between the amplification measured from earth quakes by using the ETF and AF and the amplification es timated from ambient vibrations by using the HVSR. With this, we show that the HVSR can be used as a first proxy for site response. Subsequently, HVSR curves throughout the Netherlands are estimated. The HVSR amplitude character istics largely coincide with the in situ lithostratigraphic se quences and the presence of a strong velocity contrast in the near surface. Next, sediment profiles representing the Dutch shallow subsurface are categorised into five classes, where each class represents a level of expected amplification. The mean amplification for each class, and its variability, is quan tified using 66 sites with measured earthquake amplification (ETF and AF) and 115 sites with HVSR curves. The site-response (amplification) zonation map for the Netherlands is designed by transforming geological 3D grid cell models into the five classes, and an AF is assigned to most of the classes. This site-response assessment, presented on a nationwide scale, is important for a first identification of regions with increased seismic hazard potential, for example at locations with mining or geothermal energy activities.
Subject
Earthquake
Hazard assessment
Lithostratigraphy
Seismic hazard
Seismic zone
Three-dimensional modeling
Vibration
Zonation
Netherlands
Geological Survey Netherlands
2015 Energy
To reference this document use:
http://resolver.tudelft.nl/uuid:220bc7f6-2d13-45ed-a3d4-01b01716dfa6
DOI
https://doi.org/10.5194/nhess-22-41-2022
TNO identifier
962968
Publisher
Copernicus GmbH
ISSN
1561-8633
Source
Natural Hazards and Earth System Sciences, 22 (22), 41-63
Document type
article