Two Vertical Seismic Profiles from RESPONDER acquisitions on Store Glacier, Greenland, July 2019

Two VSP datasets, acquired in July 2019 using a Silixa iDASTM distributed acoustic sensing system. Fibre-optic cable is installed in a vertical borehole, 1043 m deep, on Store Glacier, a fast-flowing outlet of the Greenland Ice Sheet. The survey site (L028) is the drained bed of a supraglacial lake, located at [70.56793°N, 50.08697°W]. The seismic source for both shots is a 7 kg sledgehammer, striking a small polyethylene impact plate. For the zero-offset shot ('RESPONDER_Jul2019_L028_ZO.sgy'), the source is located directly at the borehole top. For the offset-shot ('RESPONDER_Jul2019_L028_300mSouth.sgy'), the source is located 306.4 m south of the borehole top. Seismic VSP data are sampled every 1 m along the length of the cable. The gauge length of the iDASTM interrogator is 10 m. The time-sampling frequency of the VSP is 4000 Hz. The first trace in the VSP is located at 0 m depth. The VSPs are stacks of ~25 individual shots, and a 20-40-250-500 Hz Ormsby bandpass filter is applied. The analysis of these data is documented by the authors in the Geophysical Research Letters article "Distributed Acoustic Sensing (DAS) of Seismic Properties in A Borehole drilled on a Fast-Flowing Greenlandic Outlet Glacier".

本数据集包含2套垂直地震剖面（Vertical Seismic Profile, VSP）数据，采集于2019年7月，采用Silixa iDASTM分布式声波传感（Distributed Acoustic Sensing, DAS）系统完成野外采集。布设的光缆铺设于Store冰川（格陵兰冰盖的快速外流型冰川）内一口深度达1043米的垂直钻孔中。本次观测点位编号为L028，为一处冰面湖溃决后的湖床，地理坐标为北纬70.56793°、西经50.08697°。两套数据的震源均采用7kg大锤敲击小型聚乙烯撞击板产生地震波。其中零偏移距地震数据（文件名为"RESPONDER_Jul2019_L028_ZO.sgy"）的震源直接布置于钻孔井口位置；偏移距地震数据（文件名为"RESPONDER_Jul2019_L028_300mSouth.sgy"）的震源则布置于钻孔井口以南306.4米处。沿光缆长度方向，VSP数据的采样间隔为1米；所用iDASTM解调仪的传感基长为10米。VSP数据的时间采样频率为4000Hz，第一道采样点对应深度为0米。两套VSP数据均为约25次单次激发记录的叠加结果，且已施加20-40-250-500Hz的Ormsby带通滤波。针对该数据集的分析研究已由作者发表于《Geophysical Research Letters》期刊的论文《快速流动的格陵兰外流冰川钻孔地震属性的分布式声波传感（DAS）观测》。