The good, the bad and the ugly - lessons from and methodologies for extracting shear-wave velocity profiles from microtremor array measurements in urban Newcastle  

Authors / CoAuthors

Asten, M. | Collins, C.D.N. | Volti, T.

Abstract

We report four lessons from experience gained in applying the multiple-mode spatially-averaged coherency method (MMSPAC) at 25 sites in Newcastle (NSW) for the purpose of establishing shear-wave velocity profiles as part of an earthquake hazard study. The MMSPAC technique is logistically viable for use in urban and suburban areas, both on grass sports fields and parks, and on footpaths and roads. A set of seven earthquake-type recording systems and team of three personnel is sufficient to survey three sites per day. The uncertainties of local noise sources from adjacent road traffic or from service pipes contribute to loss of low-frequency SPAC data in a way which is difficult to predict in survey design. Coherencies between individual pairs of sensors should be studied as a quality-control measure with a view to excluding noise-affected sensors prior to interpretation; useful data can still be obtained at a site where one sensor is excluded. The combined use of both SPAC data and HVSR data in inversion and interpretation is a requirement in order to make effective use of low frequency data (typically 0.5 to 2 Hz at these sites) and thus resolve shear-wave velocities in basement rock below 20 to 50 m of soft transported sediments.

Product Type

nonGeographicDataset

eCat Id

75651

Contact for the resource

Keywords

• External PublicationConference Paper

( Theme )

• earthquakes

( Theme )

• seismic velocity

( Theme )

• geohazards

• AU-NSW

Australian and New Zealand Standard Research Classification (ANZSRC)

• Seismology and Seismic Exploration

• Published_Internal

Publication Date

2013-01-01T00:00:00

Creation Date

Security Constraints

Australian Government Security ClassificationSystem    

Classification - unclassified

Legal Constraints

Creative Commons Attribution 4.0 International Licence    

Access - restricted

Use - license

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Purpose

Maintenance Information

notPlanned

Topic Category

geoscientificInformation

Series Information

Lineage

Joint Monash University - GA collaborative project to acquire shear-wave seismic data using the SPAC method. Analysis, interpretation and reporting undertaken by Monash University.

Parent Information

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Reference System

Spatial Resolution

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Source Information

Collaborative acquisition of shear-wave seismic data using the SPAC method by Monash University and Geoscience Australia in Sydney and Newcastle. Shear-wave seismic data using the SPAC method.