Automated facies identification by Direct Push‐based sensing methods (CPT, HPT) and multivariate linear discriminant analysis to decipher geomorphological changes and storm surge impact on a medieval coastal landscape

Abstract

In AD 1362, a major storm surge drowned wide areas of cultivated medieval marshland along the north-western coast of Germany and turned them into tidal flats. This study presents a new methodological approach for the reconstruction of changing coastal landscapes developed from a study site in the Wadden Sea of North Frisia.Initially, we deciphered long-term as well as event-related short-term geomorphological changes, using a geoscientific standard approach of vibracoring, analyses of sedimentary, geochemical and microfaunal palaeoenvironmental parameters and radiocarbon dating. In a next step, Direct Push (DP)-based Cone Penetration Testing (CPT) and the Hydraulic Profiling Tool (HPT) were applied at vibracore locations to obtain in situ high-resolution stratigraphic data. In a last step, multivariate linear discriminant analysis (LDA) was successfully applied to efficiently identify different sedimentary facies (e.g., fossil marsh or tidal flat deposits) from the CPT and HPT test dataset, to map the facies' lateral distribution, also in comparison to reflection seismic measurements and test their potential to interpolate the borehole and CPT/HPT data. The training dataset acquired for the key site from coring and DP sensing finally allows an automated facies classification of CPT/HPT data obtained elsewhere within the study area. The new methodological approach allowed a detailed reconstruction of the local coastal landscape development in the interplay of natural marsh formation, medieval land reclamation and storm surge-related land losses.

Special issue: German Society for Geomorphology

“…The 26 contributions in this special issue are a representative sample of the multiple activities of the German Society for Geomorphology. They cover time scales from seconds to millions of years, observations on virtually all continents from −0.5 m (Hadler et al, 2021) to 5800 m a.s.l. (Frimberger et al, 2021).…”

“…Methodologically, all but five contributions worked in the field Holocene (e.g. Engel et al, 2021;Hadler et al, 2021;Suchodoletz et al, 2022) and Quaternary (e.g. Nottebaum et al, 2022;Richter-Krautz et al, 2021;Trappe et al, 2022) time scales.…”

“…Hadler et al ( 2021 ) present a new methodological approach which allowed a detailed reconstruction of a coastal landscape in the Wadden Sea of North Frisia in the interplay of natural marsh formation, mediaeval land reclamation and storm surge‐related land losses. The study used vibracoring, palaeoenvironmental parameter analyses of sediment samples and radiocarbon dating to decipher the sedimentary record of the Hallig Südfall geo‐archive and to reconstruct its palaeogeographic evolution.…”

“…All but one study area are located in the mid‐latitudes (the exception being the lahar study by Frimberger et al, 2021 at Mt Cotopaxi, Ecuador), with the majority (62%) in Europe, and only one in Africa (Marzen et al, 2020). The studies span a very wide elevation range, from sea level (Hadler et al, 2021) up to elevations >4000 m (Blöthe et al, 2021; Frimberger et al, 2021), and the proportions of high, mid‐ and low‐relief study areas are well balanced. With respect to temporal scales, 15 contributions refer to present‐day or present‐day and historical times, while only six contributions deal with the Holocene (e.g.…”

“…With respect to temporal scales, 15 contributions refer to present‐day or present‐day and historical times, while only six contributions deal with the Holocene (e.g. Engel et al, 2021; Hadler et al, 2021; Suchodoletz et al, 2022) and Quaternary (e.g. Nottebaum et al, 2022; Richter‐Krautz et al, 2021; Trappe et al, 2022) time scales.…”