GEOL 240Lg 1st Edition Lecture 9Outline of Last Lecture I. Review Stresses II. Plate tectonicIII. Elastic Rebound TheoryIV. Energy in rocksV. States with major earthquakes Outline Current Lecture I. Basin and ProvinceII. Western Boundary, the East Side of the Sierra NevadaIII. “Constellation” of GPS SatellitesIV. San Andreas Fault and WasatchV. Basin RangeVI. Major Earthquakes and their magnitudesCurrent Lecture- Basin and Range Province - activities we are worried about: Reno- the western boundary the east side of the sierra Nevada, sierra just means mountain range- how high is Mt. Whitney- Owens lake elevation: 4k - Sierra Nevada is the footwall- Hilton creek normal fault, e. sierra Nevada picture Salt Lake City and Wasatch front a mirror image of the Sierra NevadaThere’s lots of brick construction there  ‘til 1980 people did not appreciate that they live around this big faults (GPS site velocities showing east-west extension rate across basin and range)Wastch fault extending along mountain front Big range, big normal faults, beautiful moraines Places where you actually see the planeSan Andreas Fault and Wastch fault along the oldest planes that were studied No big earthquake in history time of WastchWhy are all the speeding records done at Salt Faults, Utah? Because it is the flattest place Lake mutt water saturated  cities built on this lake will not do well during huge earthquakes yet to come San Andreas Fault: right lateral The biggest the longest fault in California it stores out energy faster than any fault in California so it releases faster and generates the largest earthquakes ... much bigger than any south of Cascadia The dominate faultThe total rate in which it move (5cm per year) 35/50 plate rate 70% of movement is brought by San Andrea. It is not the plate boundary 5% is in the basin range the rest is east of the sierra Nevadaa thousand kilometers long, slipping 35 mm per year 27 of “ constellation” at GPS satellites in geosynchronous orbitthese satellites are microwave receivers.. encoded in them, you can tell exactly where you are inthe earth with this these are incredibly useful for earthquake signs1906 Mw 7.9 San Francisco earthquakeneed to know it was about magnitude 8 six fingers of slip It rupture a 450km length of SAF slipped ^ 5m of average slip15km down dip widthWhat happens when you go down on the earth: temperature and pressure:15 km  this is how much earthquakes go deepWhy don’t they go deeper?You increase temp and pressure and eventually you reach a point when instead of bending and breaking they just flow and then they get weaker. The other big one the san Andreas Fault has produced is:1857 Fort Tejan Mw 7.9Ruptured ^ 350km of SAF 5m of average slip15 km down dip width creeping section of SAF - 150 km long - central part of SAF- rocks slide continuously rather than storing up elastic strain energy- 1906 stopped at the North end - 1857 stopped at south endSAF, Hayward Fault, Calaveras Fault 3 major strands of SAF system in the san Francisco bay area Figure 1.. the San Fran bound train at point Reyes station that was tipped on its side during the 1906 San Fran earthquake Why did San Fran say that earthquake didn’t do any damage? Because they had a fire insurance and insurance were going to rebuild