Universität zu Köln

Martin, Aurelie, Lecocq, Thomas ORCID: 0000-0002-4988-6477, Hinzen, Klaus-G., Camelbeeck, Thierry, Quinif, Yves and Fagel, Nathalie (2020). Characterizing Stalagmites' Eigenfrequencies by Combining In Situ Vibration Measurements and Finite Element Modeling Based on 3D Scans. Geosciences, 10 (10). BASEL: MDPI. ISSN 2076-3263

Full text not available from this repository.

Abstract

Broken or deformed speleothems have been used as indicators of paleo-earthquakes since the 1990s; however, a causal link is difficult to prove except for some thin speleothems. In contrast, the presence of intact speleothems permits estimating an upper limit of the level of horizontal ground motions of past seismicity in the area. The natural frequencies of speleothems are fundamental parameters for their response to earthquakes. This study proposes a new method of in situ characterization of these natural frequencies. Tested in the Han-sur-Lesse cave (Belgian Ardennes), the method is based on recording the ambient seismic noise using three-component sensors on a stalagmite and a 3D laser scan of its shape. The ambient seismic noise records allow a precise determination of the eigenfrequencies of the stalagmite. In addition, numerical models based on the 3D scan show good consistency between measured and modeled data. The joint analysis of these two techniques concludes that the shape of the stalagmite (elliptical cross-section and shape irregularities) influence the eigenfrequencies and polarization of the modes while also causing a near-orthogonal split of natural frequencies. The motions recorded on the stalagmite show significant amplification compared to those recorded at the free surface outside the cave, which has a strong impact on seismic hazard assessment based on speleothems.

Item Type:	Journal Article
Creators:	Creators Email ORCID ORCID Put Code Martin, Aurelie UNSPECIFIED UNSPECIFIED UNSPECIFIED Lecocq, Thomas UNSPECIFIED orcid.org/0000-0002-4988-6477 UNSPECIFIED Hinzen, Klaus-G. UNSPECIFIED UNSPECIFIED UNSPECIFIED Camelbeeck, Thierry UNSPECIFIED UNSPECIFIED UNSPECIFIED Quinif, Yves UNSPECIFIED UNSPECIFIED UNSPECIFIED Fagel, Nathalie UNSPECIFIED UNSPECIFIED UNSPECIFIED
URN:	urn:nbn:de:hbz:38-316443
DOI:	10.3390/geosciences10100418
Journal or Publication Title:	Geosciences
Volume:	10
Number:	10
Date:	2020
Publisher:	MDPI
Place of Publication:	BASEL
ISSN:	2076-3263
Language:	English
Faculty:	Unspecified
Divisions:	Unspecified
Subjects:	no entry
Uncontrolled Keywords:	Keywords Language HAN-SUR-LESSE; UPPER LIMIT; INTACT SPELEOTHEMS; CAVE; PARAMETERS; KARSTIFICATION; EARTHQUAKE; COMPLEX; BROKEN; OBSPY Multiple languages Geosciences, Multidisciplinary Multiple languages
URI:	http://kups.ub.uni-koeln.de/id/eprint/31644