Ngururrpa Gravity Survey P201560 Spherical Cap Bouguer Anomaly 267GU  

Authors / CoAuthors

Geophysical Acquisition & Processing Section

Abstract

Gravity data measure small changes in gravity due to changes in the density of rocks beneath the Earth's surface. The data collected are processed via standard methods to ensure the response recorded is that due only to the rocks in the ground. The results produce datasets that can be interpreted to reveal the geological structure of the sub-surface. The processed data is checked for quality by GA geophysicists to ensure that the final data released by GA are fit-for-purpose. This Ngururrpa Gravity Survey P201560 Spherical Cap Bouguer Anomaly 267GU is a complete Bouguer anomaly grid for the Ngururrpa Gravity Survey (P201560) survey. This gravity survey was acquired under the project No. 201560 for the geological survey of WA. The grid has a cell size of 0.00466 degrees (approximately 500m). The data are given in units of um/s^2, also known as 'gravity units', or gu. A total of 4965 gravity stations were acquired to produce this grid.

Product Type

dataset

eCat Id

143890

Contact for the resource

Keywords

theme.ANZRC Fields of Research.rdf

• EARTH SCIENCES

( Data centre )

• NCI

( Discipline )

• Earth sciences

( Discipline )

• geophysics

( Feature type )

• grid

( Place )

• Australia

( Place )

• WA

( Project )

• survey 201560

( Theme )

• GADDS2.0

( Theme )

• gravity

( Theme )

• spherical cap

( Theme )

• Bouguer

( Theme )

• ground digital data

( Theme )

• geophysical survey

( Theme )

• grav

( Theme )

• grid

( Theme )

• raster

• Published_External

Publication Date

2020-03-07T00:00:00

Creation Date

2020-03-07T00:00:00

Security Constraints

Australian Government Security ClassificationSystem    

Classification - unclassified

Legal Constraints

Creative Commons Attribution 4.0 International Licence    

Access - license

Use - license

Status

completed

Purpose

Maintenance Information

notPlanned

Topic Category

geoscientificInformation

Series Information

Lineage

This Ngururrpa Gravity Survey P201560 Spherical Cap Bouguer Anomaly 267GU is a spherical cap Bouguer anomaly grid for the Ngururrpa Gravity Survey (P201560). This gravity survey was acquired under the project No. 201560 for the geological survey of WA. The grid has a cell size of 0.00466 degrees (approximately 500m). The data are given in units of um/s^2, also known as 'gravity units', or gu. A total of 4965 gravity stations were acquired to produce this grid. Three processes are required to correct the gravity observations for the effects of the surrounding topography: (1) a Bouguer correction (Bullard A), which approximates the topography as an infinite horizontal slab; (2) a correction to that horizontal slab for the curvature of the Earth (Bullard B); and (3) a terrain correction (Bullard C), which accounts for the undulations of the surrounding topography. The Spherical Cap Bouguer gravity anomalies were calculated by applying Bullard A and Bullard B corrections to the free air anomalies using a density of 2670 kg per cubic metre. These data were then gridded using the nearest neighbour algorithm from the INTREPID Geophysics software package. The processed data are checked by GA geophysicists using standard methods for assessing quality to ensure that the final data are fit-for-purpose. The final Spherical cap Bouguer anomalies grid contains data values which account for a correction due to the shape or curvature of the Earth, and provide a more accurate representation of crustal density variations beneath the Earth's surface. Details of the specifications of individual surveys held in the Australian National Gravity Database (ANGD) can be found in the Second Edition of the Index of Gravity Surveys (Wynne and Bacchin, 2009). References: Intrepid Geophysics, http://www.intrepid-geophysics.com; Wynne, P., and Bacchin, M., 2009. Index of Gravity Surveys (Second Edition). Geoscience Australia, Record 2009/07.

Parent Information

Geophysical Data Collection - gravity

UUID - c6b58f54-102c-19e9-e044-00144fdd4fa6,

eCat ID - 74512

Extents

[-22.2288, -20.337, 127.2223, 129.0255]

Reference System

GDA94 (EPSG:4283)

Spatial Resolution

Service Information

Associations

Association Type - operatedOnBy

Ngururrpa Gravity Survey P201560 Spherical Cap Bouguer Anomaly 267GU NCSS    

Association Type - operatedOnBy

Ngururrpa Gravity Survey P201560 Spherical Cap Bouguer Anomaly 267GU OPeNDAP    

Association Type - operatedOnBy

Ngururrpa Gravity Survey P201560 Spherical Cap Bouguer Anomaly 267GU WMS    

Association Type - operatedOnBy

Ngururrpa Gravity Survey P201560 Spherical Cap Bouguer Anomaly 267GU WCS    

Downloads and Links

File available for download in various formats from the GADDS2 portal  

Ngururrpa Gravity Survey P201560 Spherical Cap Bouguer Anomaly 267GU file download  

Ngururrpa Gravity Survey P201560 Spherical Cap Bouguer Anomaly 267GU NCSS  

Ngururrpa Gravity Survey P201560 Spherical Cap Bouguer Anomaly 267GU OPeNDAP  

Ngururrpa Gravity Survey P201560 Spherical Cap Bouguer Anomaly 267GU WMS  

Ngururrpa Gravity Survey P201560 Spherical Cap Bouguer Anomaly 267GU WCS  

Source Information

This Ngururrpa Gravity Survey P201560 Spherical Cap Bouguer Anomaly 267GU includes ground gravity point data for the Ngururrpa Gravity Survey (P201560) acquired for the geological survey of WA