Processed high resolution line aeromagnetic data over Pine Island Glacier Ice Shelf (2010-2011)

• Main Authors: Jordan, Tom, Ferraccioli, Fausto
• Format: Dataset
• Language: English
• Published: UK Polar Data Centre, Natural Environment Research Council, UK Research & Innovation 2020
• Subjects: "EARTH SCIENCE","SOLID EARTH","GEOMAGNETISM","MAGNETIC ANOMALIES"; "EARTH SCIENCE","CRYOSPHERE","GLACIERS/ICE SHEETS"; Aerogeophysics; Aeromagnetics; Antarctica; West Antarctica; Pine Island Glacier; Noice; Antarc*; Ice Shelf; Pine Island
• Online Access: https://dx.doi.org/10.5285/84b382c3-6b6f-4524-9807-ec7941e5620d; https://data.bas.ac.uk/full-record.php?id=GB/NERC/BAS/PDC/01355

In 2011, aerogeophysics data were acquired over Pine Island Glacier, West Antarctica on a grid comprising 30 transverse lines across the glacier, each around 20 km long, and with a spacing of roughly 500 m between the lines. The orientation of the lines was selected to be perpendicular to the surface features visible in satellite images in the central part of the ice shelf. Elevation of the ice-surface directly beneath the aircraft was simultaneously measured using a nadir-pointing laser altimeter. We present here the processed line aeromagnetic data acquired using scintrex cesium magnetometers mounted on the BAS aerogeophysical equiped Twin Otter. Data are provided as XYZ ASCII line data. : Details on survey design and the PIG mouth aeromagnetic data collection are presented in Vaughan et al. (2012). The dataset available here includes all channels from raw through to levelled, and microlevelled products. Channel naming follows SCAR/ADMAP2 data release protocols, although the order of processing steps differs from that outlined by ADMAP2 documentation. Also included in the database is a subset of lines from the BBAS survey of the catchment of Pine Island glacier. This subset includes three flow-parallel tie lines and shorter line segments roughly transverse to flow. These lines have been levelled to the high resolution grid of the PIG mouth survey, but not included in microlevelling given their contrasting orientation. Magnetic data channels and processing flow: MagR- Raw magnetic total field intensity data (nT). MagC- Raw magnetic total field intensity data (nT) compensated for aircraft roll, pitch and yaw using PicoEnvirotec software. TCorr- Tiptank corrections (nT). These include DC shifts and gradients due to aircraft noice, etc. Dummy values if not applicable. RefField- Geomagnetic reference field value for which the magnetic data has been compensated. IGRF model 2010 as implemented in Geosoft (nT). MagRTC- Compensated magnetic data corrected for tiptank events and the geomagnetic reference field. MagRTC= MagTCorr- RefField BCorr- Base station measured geomagnetic field variations. A base station was not used in the PIG mouth survey hence no BCorr has been applied. ACorr- MagRTC filtered using a low pass filter with a cut-off length of 15 fiducials to account for any remnant noise in the data. SCorr- Any DC shift applied. A +12 nT shift has been applied to P lines in the database to adjust their level to that of the rest of the survey. MagF- Final mag value before levelling. MagF= MagRTC- SCorr- ACorr MagL- Statistically levelled mag data. MagML- Microlevelled magnetic data following technique of (Ferraccioli et al., 1998). Note tie lines are not included in the microlevelled data channel. Basic channel description: Line name Line Number Flight ID Sequential flight number x x projected meters* y y projected meters* Lon Longitude WGS 1984, Lat Latitude WGS 1984, Height_WGS1984 Aircraft altitude (meters) in WGS 1984, Date Date of flight in time format e.g. 2006/01/08 Time Time (UTC) of flight e.g. 23:52:42.0 *Projected coordinates (x and y) are in Polar Stereographic: Latitude of natural origin: -71 Longitude of natural origin: 0 Scale factor at natural origin: 0.994 False easting 0 False northing 2072760.109 Positioning for the PIG mouth survey used a dual-frequency carrier-phase GPS (Vaughan et al., 2012). Positions are calculated for the phase centre of the aircraft antenna. All positions (Lat, lon and height) are referred to the WGS1984 ellipsoid. Aeromagnetic data acquired as part of BBAS project in 2004 was used for levelling. See related dataset: https://doi.org/10.5285/485e6b9b-d033-441f-8c98-b2d0efcb1d63 : No values are given for MagC, BCorr, and MagBRTC. No base station was run, and no compensation was carried out.