The branch of science that studies earthquakes is: __________ A. Earthquake Regions on Earth Question: What does the map of these earthquakes seem to resemble? _____________________________________________ _______________________________________ B. Earthquake by Definition: _____________________________________________ _______________________________________ - Caused by: - The energy: Earthquakes in PA Date Local Time Magnitude April 22, 2009 9:21 1.1 April 23, 2009 6:26 2.4 April 24, 2009 1:36 2.9 April 30, 2009 18:36 2.0 May 11, 2009 01:18 1.3 May 11, 2009 01:34 1.2 October 25, 2009 07:16 2.6 October 25, 2009 07:18 1.8 October 25, 2009 07:21 2.8 Note: Largest Earthquake in PA was: ________________________ Recently close earthquake was: ________________________ Location: Time: Magnitude: Question: Where do you notice these earthquakes occurring? _______________________________________________ Boundaries and types of Earthquakes •Build up of _________________________________ Which boundary?__________ ___ Type of Earthquake: ______________ Boundary: ___________ Plate Interaction: ___________________ Type of Earthquakes: ____________________ Boundary: _____________ Plate Interaction: ___________________ Type of Earthquakes: ___________________ Boundary: ___________ Plate Interaction: ___________________ Type of Earthquakes: ____________________ Boundary: ___________ Plate Interaction: ___________________ Type of Earthquakes: ____________________ Types of Faults Fault: ___________________________ Three Main Types: Normal, Reverse, Strike-Slip "Hanging Wall"- The surface of block ____________________________. "Footwall"- The surface or block that ____________________________. Types of Faults Earthquake Waves Origin and map location SEISMIC WAVE BASICS Characteristics of Seismic Waves •Body Waves •P and S seismic waves: _____________________________________________ P-WAVE •Primary: ____________________________________________ •Travel fastest_____________, travel through _______________ • A _______________wave, like a ________________________ S-WAVE •Secondary__________________________________ •Travel through ______________________________ •Crest & trough ______________________________ SURFACE WAVES • Seismic waves that only ________________________________ • Rayleigh wave, and Love wave • Do all the damage;__________________________ Shadow Zones • Zone in which a wave is _____________________________________ • Monitoring centers ________________________________________ Learning the Travel Time Graph How long does it take a P-wave to travel a. 1000 km: _________________ b. 2200 km: _________________ c. 3400 km: _________________ d. 4600 km: _________________ e. 5800 km: _________________ f. 6500 km: _________________ How long does it take a S-wave to travel a. 1000 km: _________________ b. 2200 km: _________________ c. 3400 km: _________________ d. 4600 km: _________________ e. 5800 km: _________________ f. 6500 km: _________________ How far does a P-wave travel in a. 1:00 min: _________________ b. 3:20 min: _________________ c. 5:40 min: _________________ d. 8:00 min: _________________ e. 9:20 min: _________________ f. 11:00 min: _________________ How far does a S-wave travel in a. 1:00 min: _________________ b. 3:20 min: _________________ c. 5:40 min: _________________ d. 8:00 min: _________________ e. 9:20 min: _________________ f. 11:00 min: _________________ Earthquakes Seismic Wave Basics Finding an Epicenter Use the data from the recording stations: Station A: San Francisco, California P-Wave arrival S-Wave arrival Calculate the time difference between P and S wave arrivals? (Subtract the S-wave from the P-wave) Station B: Denver, Colorado P-Wave arrival S-Wave arrival Calculate the time difference between P and S wave arrivals? (Subtract the S-wave from the P-wave) Station C: Missoula, Montana P-Wave arrival S-Wave arrival Calculate the time difference between P and S wave arrivals? (Subtract the S-wave from the P-wave) Difference in arrival times: Station A: San Francisco, California _________ Station B: Denver, Colorado _________ Station C: Missoula, Montana ____________ EPICENTER DISTANCES Station A: San Francisco, California _________ Station B: Denver, Colorado _________ Station C: Missoula, Montana ____________ Calculating Distances to the to the Epicenter of an Earthquake 1. How far from a seismograph is the epicenter of a quake if the difference in arrival times between the P and S waves are: a. 5:00 min: _________________ b. 8:30 min: _________________ c. 3:40 min: _________________ d. 6:20 min: _________________ 2. How far (not time) is a seismograph from the epicenter of a quake if: a. P wave arrives at 8:00:00 S wave arrives at 8:04:30 ____________________ b. P wave arrives at 12:30:00 S wave arrives at 12:37:40 ____________________ 3. If a seismograph is 7000 km from the epicenter how long will it take before a S-wave would appear? ________________ 4. If a seismograph is 2500 km from the epicenter how long will it take before a S-wave would appear? ________________ 5. What is the difference in arrival time between P and 3 Waves if the quake occurs: a. 4500 km from the seismograph? ___________________ b. 4500 km from the seismograph? ___________________ c. 2800 km from the seismograph? ___________________ 6. if a quake is recorded at a seismograph station at 11:00:00. This earthquake was 3600 km from the epicenter, at what time did the quake actually occur? Origin time: Locating an Epicenter on a Map through Triangulation Use the three seismograms to determine the location of an earthquake Location 1: Houston, Texas Location 2: Chicago, Illinois Location 3: Seattle, Washington Seismograph Arrival Time Difference in Distance to Station Arrival Time Epicenter P-wave S-wave Earthquake Measurement Scales Richter Scale • Measures the _____________________ to gauge an ______________________________________ • Measures the energy ___________________________ • Uses a _______________to measure an earthquakes’ strength. Mercalli Scale • Measures the amount of_____________________________. • Rating depends on amount____________________________. • No _________________________measurements taken. .