Abstract:
A British Antarctic Survey Twin Otter and survey team acquired 8,300 line-km of magnetic data during the Austral summer of 1998/99. Gravity and radio-echo data were acquired simultaneously with the magnetic data at a compromise constant barometric height of 2,200 m, which provides a terrain clearance of 100 m over the highest peaks. Two separate surveys were conducted; one at 5 km line spacing (tie lines at 20 km) over and stretching beyond the southern extent of the Forrestal range (main survey), and one at 2 km line spacing (tie lines at 8 km) covering the Dufek Massif (detailed survey). Wing-tip-mounted cesium vapour magnetometers acquired data at 10 Hz, which was resampled to 1 Hz after deletion of data corrupted by the radio echo transmissions. It is not possible to compensate the magnetic data for maneuver noise after this process as the data are under-;sampled with respect to maneuver noise. However, because gravity data was being acquired at the same time, turbulent conditions were avoided and so maneuver noise was at a minimum. Ashtech Z12 dual frequency GPS receivers were used for survey navigation. Pseudorange data were supplied to a Picodas PNAV navigation interface computer, which was used to guide the pilot along the pre-planned survey lines. The actual flight path was recovered, using carrier-phase, continuous, kinematic GPS processing techniques. All magnetic and pseudorange navigation data were recorded at 1 Hz on a Picodas PDAS 1000, PC-based data acquisition system.
Data were de-spiked and then smoothed (~100 m low pass filter), before re-sampling from 10 to 1 Hz. The data were IGRF corrected, leveled and reduced to the pole in the field. A 2.5 km cell grid was produced. The negative bias to the anomaly amplitudes is a result of the poorly defined IGRF in this area.
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.
Keywords:
Aerogeophysics, Aeromagnetics, Antarctica
Ferris, J. (2020). Processed line aeromagnetic data over the Dufek Massif, Pensacola Mountains (1998/99 season) (Version 1.0) [Data set]. UK Polar Data Centre, Natural Environment Research Council, UK Research & Innovation. https://doi.org/10.5285/c8d67254-7a66-4ec4-9df8-9dc1c254add5
| Use Constraints: | This data is covered by a UK Open Government Licence (http://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/) Further by downloading this data the user acknowledges that they agree with the NERC data policy (http://www.nerc.ac.uk/research/sites/data/policy.asp), and the following conditions: 1. To cite the data in any publication as follows: Ferris, J. (2020). Processed line aeromagnetic data over the Dufek Massif, Pensacola Mountains (1998/99 season) (Version 1.0) [Data set]. UK Polar Data Centre, Natural Environment Research Council, UK Research & Innovation. https://doi.org/10.5285/C8D67254-7A66-4EC4-9DF8-9DC1C254ADD5 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. |
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| Creation Date: | 2020-06-29 |
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| Dataset Progress: | Complete |
| Dataset Language: | English |
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| Parameters: |
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| Personnel: | |
| Name | PDC BAS |
| Role(s) | Metadata Author |
| Organisation | British Antarctic Survey |
| Name | Dr Julie K Ferris |
| Role(s) | Investigator |
| Organisation | British Antarctic Survey |
| Parent Dataset: | N/A |
| Reference: | Main references: Ferris, J.K., Johnson, A.C., Storey, B.C., 1998. Form and extent of the Dufek intrusion, Antarctica, from newly compiled aeromagnetic data. Earth and Planetary Science Letters, 154 185-202. https://doi.org/10.1016/S0012-821X(97)00165-9 Ferris, J.K., Storey, B.C., Vaughan, A.P.M., Kyle, P.R., Jones, P.C., 2003. The Dufek and Forrestal intrusions, Antarctica: a centre for Ferrar Large Igneous Province dike emplacement? Geophysical Research Letters 30 DOI: 10.1029/2002GL016719 Fremand, A. C., Bodart, J. A., Jordan, T. A., Ferraccioli, F., Robinson, C., Corr, H. F. J., Peat, H. J., Bingham, R. G., and Vaughan, D. G.: British Antarctic Survey's aerogeophysical data: releasing 25 years of airborne gravity, magnetic, and radar datasets over Antarctica, Earth Syst. Sci. Data, 14, 3379-3410, https://doi.org/10.5194/essd-14-3379-2022, 2022. |
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| Lineage: | DUFEK aeromagnetic dataset available here includes fully processed and levelled products. Details of data acquisition and processing steps are presented in Ferris et al., (1998, 2003). Channel description: Basic Channels x x projected meters* y y projected meters * Lon Longitude WGS 1984, Lat Latitude WGS 1984, Mag processing channels MagF Final magnetic data value before levelling (nT) MagL Statistically levelled magnetic data. Tie lines levelled to normal lines initially. (nT) *Projected coordinates (x and y) are in Lambert conic conformal with two standard parallels defined as follows: Latitude of false origin: -80 Longitude of false origin: 80 Latitude of 1st standard parallel -83 Latitude of 2nd standard parallel -77 False easting 2000000 False northing 2000000 Positioning for the Dufek survey uses Ashtech Z12 dual frequency GPS recievers (Ferris et al, 2003). Positions are calculated for the phase centre of the aircraft antenna. All positions (Lat, lon and height) are referred to the WGS1984 ellipsoid. |
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| Temporal Coverage: | |
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| Start Date | 1999-01-01 |
| End Date | 1999-01-31 |
| Spatial Coverage: | |
| Latitude | |
| Southernmost | -84.47255 |
| Northernmost | -82.2974 |
| Longitude | |
| Westernmost | -63.66227 |
| Easternmost | -44.25869 |
| Altitude | |
| Min Altitude | N/A |
| Max Altitude | N/A |
| Depth | |
| Min Depth | N/A |
| Max Depth | N/A |
| Data Resolution: | |
| Latitude Resolution | N/A |
| Longitude Resolution | N/A |
| Horizontal Resolution Range | 30 meters - < 100 meters |
| Vertical Resolution | N/A |
| Vertical Resolution Range | N/A |
| Temporal Resolution | N/A |
| Temporal Resolution Range | N/A |
| Location: | |
| Location | Antarctica |
| Detailed Location | Dufek Massif |
| Location | Antarctica |
| Detailed Location | Pensacola Mountains |
| Sensor(s): |
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| Source(s): |
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| Distribution: | |
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| Distribution Media | Online Internet (HTTP) |
| Distribution Size | 14 MB |
| Distribution Format | ASCII |
| Fees | N/A |
| Data Storage: | This dataset constains 1 ASCII XYZ file: -DUFEK_Mag.XYZ ~14MB |