Seismic Imaging of Esker Sediments within the Satakunta Sandstone Depression in Köyliö, SW Finland
2016 (English)Conference paper, Abstract (Refereed)
The Satakunta sandstone depression infilled by the Pori-Koski interlobate esker sediments hosts a major high-quality groundwater reservoir in Köyliö, SW Finland. These up to 100 m thick sediments were delineated for the first time down to bedrock level by high-resolution reflection seismic method using a newly developed landstreamer consisting of 80-3C MEMs (micro electro mechanical) broadband sensors together with 50 wireless recorders connected to 10 Hz geophones to obtain greater depth penetrations. The 5-day survey resulted in about 5 km long seismic data (2-4 m receiver and shot spacing) and two profiles. Indications of crystalline basement are lacking in the tomography sections, implying that the (fractured) Rapakivi granite area extends further southeast than expected. The sandstone contact position was also ca. 500 m further to the east than expected. The sandstone depression and infilling esker sediments and the bedrock level were shown with good accuracy in both tomographic model and the reflection section. The hydraulically conductive esker core does not follow the sandstone contact and is underlain by older sediments. This case study illustrates the capability of high-resolution seismic surveys with the parameters used in this study for hydrogeological investigations and in particular in thick glacial sediments.
Place, publisher, year, edition, pages
IdentifiersURN: urn:nbn:se:uu:diva-303362DOI: 10.3997/2214-4609.201601957OAI: oai:DiVA.org:uu-303362DiVA: diva2:971654
Near Surface Geoscience 2016 - 22nd European Meeting of Environmental and Engineering Geophysics
FunderSwedish Research Council Formas