Mx in Canada’s 4th Generation seismic hazard model

Documentation

http://earthquakescanada.nrcan.gc.ca/hazard/OF4459/index_e.php

Developed ~1994-1997

Finalized 2003

Implemented in 2005 code

John AdamsPresentation for USGS Mmax meeting Golden 2008 09 09

4th Generation model

Figure A11–1

Magnitude-recurrence for eastern

Canada

1929 Grand Banks

1933 Baffin

Bay

7.37.5 8.0

Figure A11–2

Stable Craton Core (SCC) rates and Mmax Fenton and Adams, 1997; Fenton et al 2006

One M6.5 per decade Places like Canadian

Shield!

http://earthquakescanada.nrcan.gc.ca/hazard/2006/2006FentonAdamsHalchukGEGE.pdf

Figure A11–3

Floor Hazard estimates - Three rates to capture uncertainty:

B) Observed North American shield activity rate Wt = 0.4

A) Global earthquake activity of continental shields Wt = 0.4

C) Rate for central Canada not in a source zone Wt = 0.2

Then, seismic hazard computed for centre of large zone

Figure A11–4

Uniform Hazard Spectrasoil class C

Floor UHS for 2%/50yr

Figure A11–5

This is a 1999 deaggregation using EZ-Frisk. Details may have changed, but pattern will be the same.

Figure A11–6

Floor value

Figure A11–7

Mesozoic rifted margin

Mobs ~7.4Weighted branches best, upper, lower

7.5 8.0 7.30.68 0.16 0.16

Plenty of potential large faults -> M8

Figure A11–8

Paleozoic rifted margin

Mobs ~7.0Weighted branches best, upper, lower

7.5 7.7 7.20.68 0.16 0.16

Enough potential large faults

Figure A11–9

Interior ?slightly extended

Mobs ~5.0Weighted branches best, upper, lower

7.0 7.2 6.80.68 0.16 0.16

potential large faults?

insensitive to Mmax

consistent with SCC

Figure A11–10

Paleozoic rifted margin

Mobs ~5.0Weighted branches best, upper, lower

7.5 7.7 6.00.68 0.16 0.16

potential large faults?

insensitive to Mmax

inconsistent with SCC!

Figure A11–11