10/10/18 SIO15-18: Lecture 6 Earthquake Hazards Fig. 6.1b Fig. 1.2 (study guide) Hawaii 10/15/06; 7:07 HST Northridge, CA 01/17/94; 4:31 PST Mag. 6.7 Mag. 6.7 0 fatalities 72 fatalities landslides on Hawaii $12.5 billion damage $200 Mio damage (61 buildings) 1g ground acceleration power outage on Oahu SIO15-18: Lecture 6 Earthquake Hazards Source: wikipedia.org 1
10/10/18 Hawaii 5/4/18; 12:32 HST Mag. 6.9 intensity VIII shaking; 0 fatalities south flank of Kilauea/volcanism minor local tsunami (40 cm) damage to buildings, roads; landslides Hilina slump moved 2 feet SIO15-18: Lecture 6 Earthquake Hazards Source: wikipedia.org Fig. 1.x Bam, Iran 12/26/03; 5:26 local time Northridge, CA 01/17/94; 4:31 PST Mag. 6.6 Mag. 6.7 at least 26,000 fatalities 72 fatalities displaced 90% of residents $12.5 billion damage destroyed 70% of modern city damaged major freeway SIO15-18: Lecture 6 Earthquake Hazards Source: wikipedia.org 2
10/10/18 Fig. 6.2b � 60% of old, poorly-built structures collapsed � structures built after 1984 survived � 1000 fatalities � poor soil (old land fill sites or steep slopes) � lack of urban planning and land studies Image: S. Marshak “Earth, Portrait of a Planet” brick SIO15-18: Lecture 6 Earthquake Hazards • local large tsunami (7 m); Palu - tsunami warning issued but the called off • landslides/mudflows - power outage/>500 cell phone towers - poorly functioning warning system • liquefaction; Palu • > 70,000 homes damaged strike-slip EQ • > 2000 fatalities (n1000 missing) so why tsunami?? -> submarine landslide source:Wikipedia, NYT SIO15-18: Lecture 6 Earthquake Hazards 3
10/10/18 link for CNN video on liquefaction: https://www.cnn.com/2018/10/03/asia/liquefaction-earthquake-indonesia-intl/index.html SIO15-18: Lecture 6 Earthquake Hazards • did the earthquake trigger the volcanic eruption? …. most likely not as volcano was active before EQ 7 Jun 2008 source:Wikipedia stratovolcano one of Sulawesi’s most active Strombolian style pyroclastic flows; lava flows 10/3/18 ash 6 km high SIO15-18: Lecture 6 Earthquake Hazards 4
10/10/18 POPQUIZ #2 YOUR FULL NAME AND STUDENT ID# no credit if one is missing Compared to long faults, large earthquakes are • less likely • more likely • equally likely on shorter faults? Code of Conduct: you may ask your neighbor you may consult your notes, book, online you may NOT write and/or submit your friend’s popquiz SIO15-18: Lecture 6 Earthquake Hazards • Florida panhandle/ Alabama • but Georgia, Carolinas also in path • formed in GoM • landfall 1 pm Wed source:NOAA SIO15-18: Lecture 6 Earthquake Hazards 5
10/10/18 source:NOAA • Florida panhandle/ Alabama • but Georgia, Carolinas also in path SIO15-18: Lecture 6 Earthquake Hazards Fig. 6.11 Fig. 6.13 Sumatra-Andaman 26 Dec 2004 Tohoku 11 Mar 2011 • Mw=9.1; 10m tsunami • Mw=9.0; 40m tsunami • 3rd largest EQ in 100 years • 4th largest EQ in 100 years • > 240,000 fatalities • < 20,000 fatalities • in ocean, along subduction zone • in ocean, along subduction zone source:Wikipedia source:Wikipedia SIO15-18: Lecture 6 Earthquake Hazards 6
10/10/18 Chapter 6 (incomplete) wave height depends on • wind speed SIO Pier Dec 27 and Dec 29 2006 • duration of wind • fetch λ from cm deep-water waves to n100 m (D > λ /2) waves do not sense bottom particle motion circular v = λ /T or v=g T/(2 π ) shallow-water waves (D < λ /20) particle motion elliptical SIO15-18: Lecture 6 Earthquake Hazards Fig. 6.17 • caused by submarine EQs with vertical displacement • extremely long wavelength (200 km) • shallow-water waves -> speed depends on water depth D • 720-800 km/h!!! • not noticeable at sea • built up coming on shore ( >10m) • 15 min between peak and trough v= √ 10ms -2 •4000m=200m/s=720km/h SIO15-18: Lecture 6 Earthquake Hazards Image: S. Marshak “Earth, Portrait of a Planet” 7
10/10/18 Fig. 6.15 Parking Meters in Hilo, HI SIO15-18: Lecture 6 Earthquake Hazards Fig. 6.23 � people ignore warning � people forget what to do SIO15-18: Lecture 6 Earthquake Hazards 8
10/10/18 Fig. 6.20 26 December 2004 Sumatra-Andaman Tsunami � partial warning system � critical components missing � sporadic tsunami history � poor tsunami education Source: NOAA SIO15-18: Lecture 6 Earthquake Hazards Fig. 6.20 link for previous page: https://upload.wikimedia.org/wikipedia/commons/thumb/4/47/2004_Indonesia_Tsunami_Complete.gif/250px-2004_Indonesia_Tsunami_Complete.gif SIO15-18: Lecture 6 Earthquake Hazards 9
10/10/18 Predicted Heights of Japan Tsunami Fig. 6.19 Background info: 27 March 1964 Good Friday Alaska EQ Source: NOAA/wikipedia 12 fatalities in Crescent City SIO15-18: Lecture 6 Earthquake Hazards Predicted Heights of Samoa Tsunami Crescent City, CA 04:28 23:11 21:28 PDT 13:11 HST 17:48 Mw=8.1; Mercalli intensity VI Source: NOAA largest EQ in 2009 tsunami locally up to 14 m > 189 fatalities SIO15-18: Lecture 6 Earthquake Hazards 10
10/10/18 Fig. 6.20 link for animation of Samoa tsunami: https://upload.wikimedia.org/wikipedia/commons/4/4b/Samoa_tsunami_animation_20090929_samoa_a.ogv SIO15-18: Lecture 6 Earthquake Hazards Fig. 6.24 29 September 2009 Samoa Tsunami If you felt an EQ Source: NOAA � flee when there was an EQ and you are within 1mi of beach � you have at least 15min If EQ was distant � watch tide calendar � flee when low tide suspicious � you have at least 15min stay away from beach for many hours!!! SIO15-18: Lecture 6 Earthquake Hazards 11
10/10/18 Samoa Tsunami Observed at Crescent City Tide Gauge SIO15-18: Lecture 6 Earthquake Hazards 2010 Tsunami Warning and Preparedness Report by NRC (9/27/10 LA Times) “since 2004 NOAA improved ability to detect and forecast tsunami” “many coastal communities in U.S. still face challenges in responding to a tsunami that arrives less that 1h after triggering event” “tsunami rare enough to give false sense of security” “if source is close to shore [only minutes to tsunami] public needs to recognize natural cues” SIO15-18: Lecture 6 Earthquake Hazards 12
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