Figure A8–1 NRC Workshop on Mmax in the Central and Eastern U.S.EQ Hazards WorkshopSeptember 9-10, 2007 USGS, Golden, CO U.S. Department of the Interior U.S. Geological Survey
Figure A8–2 • Walter D. Mooney USGS-Menlo Park • Mmax in Cratons • Outline: • Introduction • Continental Evolution • Earthquakes and Tectonics • Lithospheric Structure • Lith-EQ Correlation (Mmax) • Conclusion: Mmax = 6.8 (?)
Figure A8–3 North American Geology
Figure A8–4 3.0 Ga (Archean): Formation of Cratons Diamonds form here
Figure A8–5 2.0 Ga (Early Proterozoic): Suturing of Cratonic Blocks
Figure A8–6 1.0 Ga (Late Proterozoic): Mantle Metasomatism at Lithospheric Suture, Intraplate Zone of Weakness Earthquake
Figure A8–7 • Schulte, S. M., and Mooney, W. D., 2005, An updated global earthquake catalogue for stable continental regions: reassessing the correlation with ancient rifts: Geophysical Journal International, v. 161, p. 707-721.
Figure A8–8 Extended margin earthquakes. Red circles denote earthquakes that are associated with extended margins, green circles denote events that are possibly associated with extended margins. Regions of concentrated seismicity are numbered.
Figure A8–9 Interior rift earthquakes. Red circles identify earthquakes that are associated with interior rifts, green circles identify events that are possibly associated with interior rifts. Regions of concentrated seismicity are numbered.
Figure A8–10 Non extended crust earthquakes. Earthquakes are indicated with blue circles. Regions of concentrated seismicity are numbered.
Figure A8–11 Figure 9. Eastern United States, taken from the Exxon tectonic map of the world [Exxon, 1985]. Rifts have been highlighted in red and blue. Earthquakes from the database have been plotted on top. Red circles denote events associated with extended crust, green circles denote events that might be associated with extended crust. Events that occurred within non-extended crust are indicated in blue. Earthquakes that occurred within the St. Lawrence depression are indicated in orange.
Figure A8–12 Lithospheric Root
Figure A8–13 Model of Precambrian Lithosphere
Figure A8–14 Lithosphere is Generally in a State of Failure Equilibrium
Figure A8–15 Tomographic Model 6,000 5,600 5,200 4,800 4,400 4,000 3,600
Figure A8–18 Number of Earthquakes
Figure A8–19 Number of Earthquakes
Figure A8–20 Number of Earthquakes
Figure A8–21 Number of Earthquakes
Figure A8–22 Magnitude of Earthquakes