Innovative Short-Term Synchronous-Asynchronous Ambient Noise Tomography Unveiled for Urban Karst Exploration

[alanw]

Lots and lots of maths and science, then This sophisticated imaging process revealed two prominent low-velocity anomalies at depths between 40 and 60 meters, correlating closely with karst cave systems identified independently by drilling data. It does seem to rely on the presence of "seismic ambient noise", presumably vehicle traffic, etc. however.

Innovative Short-Term Synchronous-Asynchronous Ambient Noise Tomography

A groundbreaking study recently published in the prestigious journal Engineering introduces an innovative method for investigating urban geohazards, with a particular focus on the detection and

scienmag.com

 

[wellyjen]

Lots and lots of maths and science, then This sophisticated imaging process revealed two prominent low-velocity anomalies at depths between 40 and 60 meters, correlating closely with karst cave systems identified independently by drilling data. It does seem to rely on the presence of "seismic ambient noise", presumably vehicle traffic, etc. however.

Innovative Short-Term Synchronous-Asynchronous Ambient Noise Tomography

A groundbreaking study recently published in the prestigious journal Engineering introduces an innovative method for investigating urban geohazards, with a particular focus on the detection and

scienmag.com

Or get lots of your mates to jump up and down while you run the data gathering.

 

[alanw]

Or get lots of your mates to jump up and down while you run the data gathering.

Quake it off: Taylor Swift concerts shake Edinburgh - British Geological Survey

Seismometers around Edinburgh were triggered by the rapturous Murrayfield crowds over the weekend.

www.bgs.ac.uk

 

[ChrisB]

Ambient noise can be quite useful. To understand is structure is vulnerable to earthquakes, one useful bit of data is it's natural vibration frequency. This was successfully tested on Swiss dam by measuring it's response to gusts of wind on the concrete face.

The technique in the link, with generated noise rather than ambient, should be capable of finding caves - maybe somebody in BGS or the like could develop something dual purpose - for urban cavities and rural caves?

 

[TheBitterEnd]

with generated noise rather than ambient

Obviously the oil and gas industry uses "generated noise" for seismic surveys but I wonder how much this technique is dependent on the noise coming from a large number of sources widely distributed around the study area?

 

[Andy Farrant]

We already use 2D passive seismic surveys at BGS to help identify subsurface features. These rely on natural background seismic noise rather than setting off explosions or using vibroseis trucks. It is good for the shallow subsurface, for example picking up buried glacial channels/valleys and faults. Not sure how useful it will be for picking up voids as the seismic noise needs a good reflector. 3D tomography is a more sophisticated, as you need lots of instruments, the researchers used 197 nodal seismic receivers, arranged with an average station spacing of just seven meters. interesting though...