Earthquake Booming

[Richard]

Talking with some friends from near Scargill today, they and a number others in the area have been hearing a lot of boom sounds coming from the ground, the sound started a few days before the 5.7 hit, sometimes a boom is followed by a quake other times just the sound only. A woman i know by the name of Sue was sitting reading when one major boom hit, she reckons it came from below the house and described it as been like very close thunder but only louder, so loud the house was vibrating, they are still happening everyday. A meeting was held just after the first 5.7 by a team of Geonet scientists and the local residences, the ground booming was raised to which the Geonet people really had no answers for.
It seem that there's still a lot to learn what forces taking place during periods of seismic disturbance.

[NZ Thunderstorm Soc]

We had 'booming' here in West Melton after the initial September the 4th quake in 2010.
Sounds heard below the ground,. with no quakes or anything, but nothing like what your friends are saying from Scargill..
Interesting

[Richard]

Even more interesting is they are getting a number of what they describe as 'horrible shunting type quakes' that are not showing up on the GeoNet web page.

[Storm Struck]

If its a local shake in the 2.0m to 2.9m all you will hear is a loud boom, kinda like a giant bowling ball rolling under the house. Its not enough to rattle the house but enough to be heard if sitting down.

[NZ Thunderstorm Soc]

We got a lot of short, sharp shocks, in 2010 which would of been about 5 on the Richter Scale, which Geonet never reported despite me filling out the associated report form regarding such quakes.
They didn't show up even on Chris Crowes website as well.
That's why I gave up recording "Did you feel it" reports on the Geonet site.

[Richard]

If its a local shake in the 2.0m to 2.9m all you will hear is a loud boom, kinda like a giant bowling ball rolling under the house. Its not enough to rattle the house but enough to be heard if sitting down.

Theyve been described as sounding like what's in the video, only single booms lasting a second


https://www.youtube.com/watch?v=JArPkrS4LYQ

[Orion]

Well, Richard, for what it's worth I came across that same video a week ago after noticing odd sounds around here on the morning of December 4. So much so that by lunchtime I had emailed my Spies, mentioning the "unnamed bumps and bangs around the place outdoors" and that "My house has been creaking much more than usual - hasn't creaked so much since November 14".

Also, after that first quake on November 14 I set up my "earthquake indicator" (refer my post of January 3 2012 which I've quoted below) and observed the same slight but constant movement of the water surface for a couple of hours after that big quake.

[ Orion on Tue 03/01/2012 08:13 in Canterbury Earthquakes thread:

"Yesterday morning about 6.30am I set up my Earthquake Indicator Mark I model, a 1.5l plastic bottle half-filled with water coloured with red food-colouring, laid on its side on the windowsill. From where I sat I could clearly see the reflection on the surface of the liquid. It was constantly quivering for a couple of hours, before going as still as I'd expected it to be. I can only suppose that showed some sort of subterranean vibration reaching us, even though I noticed no more shaking. [No other variables.] How extraordinary...." ]

All very interesting

[Richard]

Yes it is very interesting, and that the experts from Geonet dont know what's causing the booms too, they are are different to the rumbles often heard before a quake. I would love to be able to hear one for myself.

[Razor]

Same as the sort of thing that happened around us for years after September 2010/ Feb 2011. We're at the foot of the Port Hills. Often very local booms, or small shunts, often only notice in our immediate suburb. Usually measureable on the seismograph and later tied to a local and shallow ballpark 2.0 (for eg) shake.

Still get the odd one these days, the cats hate them!

[Orion]

Just recording that over the past ~48 hours or so I've been hearing occasional bumps and bangs, as if doors were slamming somewhere nearby - just now heard a muffled 'thump'.

[Richard]

Interesting.
Talking with friend from Greta valley, the same folks in the leading post, they had more thumps or booming just a few weeks. Looked on Canterbury quake live they had two small shakes at that time to there east.

[Richard]

Just recording that over the past ~48 hours or so I've been hearing occasional bumps and bangs, as if doors were slamming somewhere nearby - just now heard a muffled 'thump'.

Nothing showing on Canterbury quake live. Going by what I understand about these thumps and bangs is they dont need to be very strong shakes at all,