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:

Ferraccioli, F., & Jordan, T. (2020). High resolution aeromagnetic line data in the Ross Sea Rift collected for the ANDRILL pre-site survey (2008-09 season) (Version 1.0) [Data set]. UK Polar Data Centre, Natural Environment Research Council, UK Research & Innovation. https://doi.org/10.5285/74DF4192-7C80-4FFA-B890-4B344CFC1BEF

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:

The ANDRILL aeromagnetic dataset includes all channels from raw through to levelled and microlevelled products. This survey forms part of the ANDRILL-UK Coulman high project investigation. Information about this project can be found at http://www.andrill.org/static/CH_Science.html. Channel naming follows SCAR/ADMAP2 data release protocols. Key data processing steps are described below, and a definition of all channels is in the table.

Note in the database split by line the sections are defined as follows L= main survey grid lines, T=main survey tie lines.

Magnetic data channels and processing flow:

MagR- Raw magnetic total field intensity data (nT).

TCorr-Corrections applied for tip tank events.

MagR_TCorr- MagR corrected for tip tank events.

RefField- Geomagnetic reference field value for which the magnetic data has been compensated. IGRF model 2005 as implemented in Geosoft (nT).

MagRT- Raw magnetic value adjusted for Tip tank events and geomagnetic reference field values. MagRT= MagR_TCorr- RefField.

BCorr- Low pass filtered (60 minute) magnetic base station correction.

MagBRT- calculated as MagBRT= MagRT- Bcorr.

MagF- Final mag value before levelling. No additional corrections applied so MagF=MagBRT

MagL- Statistically levelled mag data.

MagML- Microlevelled magnetic data following technique of (Ferraccioli et al., 1998).

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 Lambert conic conformal with two standard parallels defined as follows:

Latitude of false origin: -74.018118

Longitude of false origin: 179

Latitude of 1st standard parallel -72.66666666667

Latitude of 2nd standard parallel -75.33333333333

False easting 1444000

False northing 1123000

Positioning for the ANDRILL HRAM survey uses kinematic differential GPS.