Further by downloading this data the user acknowledges that they agree with the NERC data policy (), and the following conditions:

1. To cite the data in any publication as follows:

Jordan, T., & Ferraccioli, F. (2020). Processed high resolution line aeromagnetic data over Pine Island Glacier Ice Shelf (2010-2011) (Version 1.0) [Data set]. UK Polar Data Centre, Natural Environment Research Council, UK Research & Innovation. https://doi.org/10.5285/84B382C3-6B6F-4524-9807-EC7941E5620D

2. The user recognizes the limitations of data. Use of the data is at the users' own risk, and there is no warranty as to the quality or accuracy of any data, or the fitness of the data for your intended use. The data are not necessarily fully quality assured and cannot be expected to be free from measurement uncertainty, systematic biases, or errors of interpretation or analysis, and may include inaccuracies in error margins quoted with the data.

Methodology:

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

Data quality:

No values are given for MagC, BCorr, and MagBRTC. No base station was run, and no compensation was carried out.