7.0 Earthquake in New Zealand

[Aaron Brooks Wolters]

WOW!! Glad to hear that everyone's OK so far. You guys take care.

 

[syscom3]

Apart from the Port Hills in Christchurch most of the Canterbury Plains is made up of alluvial terrace gravels and loess deposited by glaciers etc, and transported and deposited by braided river systems. During earthquakes these can act almost like a dampener (as opposed to volcanic rocks, for example, which can exacerbate shockwaves). The biggest problem in Christchurch, and (probably) the prime cause of damage, is liquification. I'm kind of simplifying things and there are probably geologists who would cringe, but I'm pretty sure I have the basics right.
Bottom line is that all of us New Zealanders are thankful that there was not a major death toll.

You have it backwards .... the loose unconsolidated sediment and sands will cause liquefaction and amplify the shaking. The solid bedrock absorbs the energy. That's what happened in the 1994 Northridge quake.

 

[DerAdlerIstGelandet]

You have it backwards .... the loose unconsolidated sediment and sands will cause liquefaction and amplify the shaking. The solid bedrock absorbs the energy. That's what happened in the 1994 Northridge quake.

1964 Good Friday Earthquake in Anchorage as well.

 

[Vic Balshaw]

Glad your safe and sound Daniel and boy, what a buzz it would have been once you had come to terms with the scary bits.

 

[Torch]

Ditto on the above remarks, Wonder if better building codes spared people compared to other EQs