Darss Sill shallow water OBS Test

For broadband ocean bottom seismometer (OBS) data, external noise is typically more pronounced than on seismometers installed onshore. However, the sources of this external noise are only partly understood. In particular, the impact the instrument design (form-factor of the floatation, pressure vessel, hight-to-width ratio) has on the amplitude of external noise is not fully understood. As a developer of OBS systems, K.U.M. Kiel GmbH has deployed two different types of OBS systems side-by-side for a period of 77 days. Both instruments included the same seismic sensor, a Nanometrics Trillium Compact 120 OBS. Station LOBS was a K.U.M. LOBSTER-type instrument carrier (https://jlsrf.org/index.php/lsf/article/view/165) which is the main instrument type in the DEPAS pool “German instrument pool for amphibian seismology”(https://www.awi.de/en/science/geosciences/geophysics/methods-and-tools/ocean-bottom-seismometer/depas.html). Station NEUA was a more recently developed system of the K.U.M. NAMMU-Type instrument, that has a completely different design (https://www.kum-kiel.de/products/nammu.html), with a single flotation, a single pressure tube containing the seismometer, datalogger and batteries. The side-by-side deployment of the different instruments allows a direct comparison and the availability of the oceanographic and meteorological data from the nearby metocean station DARSS-SILL (https://www.io-warnemuende.de/marnet-darss-sill.html) allows a detailed investigations of the instrument-design-related noise sources at OBS stations. Waveform data is available from the GEOFON data centre, under network code 1Q.

对于宽频海底地震仪（Ocean Bottom Seismometer, OBS）数据而言，其外部噪声通常比陆上部署的地震仪更为显著。然而，目前学界仅部分了解这类外部噪声的成因。具体而言，仪器设计（浮体外形、耐压容器、高宽比）对外部噪声幅值的影响尚未完全明晰。作为海底地震仪系统的研发厂商，K.U.M. Kiel GmbH将两款不同型号的海底地震仪系统并排部署了77天。两款仪器搭载了同款地震传感器——Nanometrics Trillium Compact 120 OBS。LOBS台站采用K.U.M. LOBSTER型仪器搭载平台（链接：https://jlsrf.org/index.php/lsf/article/view/165），该平台是DEPAS库"德国两栖地震学仪器池"（链接：https://www.awi.de/en/science/geosciences/geophysics/methods-and-tools/ocean-bottom-seismometer/depas.html）中的主力仪器类型。NEUA台站则采用K.U.M. NAMMU型仪器的最新研发系统，其设计与前者完全不同（链接：https://www.kum-kiel.de/products/nammu.html），仅配备单个浮体与单根耐压舱，舱内集成地震传感器、数据采集器与电池组。两款仪器的并排部署可实现直接对比，加之附近的DARSS-SILL海洋气象站（链接：https://www.io-warnemuende.de/marnet-darss-sill.html）提供的海洋与气象数据，可对OBS台站中与仪器设计相关的噪声源开展细致研究。波形数据可通过GEOFON数据中心获取，其网络编码为1Q。