10/10/18 SIO15-18: Lecture 6 Earthquake Hazards Fig. 6.1b Fig. - - PDF document

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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

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SIO15-18: Lecture 6 Earthquake Hazards SIO15-18: Lecture 6 Earthquake Hazards

Northridge, CA 01/17/94; 4:31 PST

Mag. 6.7

72 fatalities $12.5 billion damage 1g ground acceleration

Hawaii 10/15/06; 7:07 HST

Source: wikipedia.org

Mag. 6.7

0 fatalities landslides on Hawaii $200 Mio damage (61 buildings) power outage on Oahu

Fig. 1.2 (study guide)
Fig. 6.1b

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SIO15-18: Lecture 6 Earthquake Hazards

Hawaii 5/4/18; 12:32 HST

Source: wikipedia.org

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

Bam, Iran 12/26/03; 5:26 local time

Mag. 6.6

at least 26,000 fatalities displaced 90% of residents destroyed 70% of modern city Northridge, CA 01/17/94; 4:31 PST

Source: wikipedia.org

Mag. 6.7

72 fatalities $12.5 billion damage damaged major freeway

Fig. 1.x

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SIO15-18: Lecture 6 Earthquake Hazards

Image: S. Marshak “Earth, Portrait of a Planet”

brick

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

SIO15-18: Lecture 6 Earthquake Hazards

local large tsunami (7 m); Palu
landslides/mudflows
liquefaction; Palu
> 70,000 homes damaged
> 2000 fatalities (n1000 missing)
tsunami warning issued but the called off
power outage/>500 cell phone towers
poorly functioning warning system

strike-slip EQ so why tsunami?? -> submarine landslide

source:Wikipedia, NYT

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SIO15-18: Lecture 6 Earthquake Hazards

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

source:Wikipedia

7 Jun 2008 stratovolcano

ne of Sulawesi’s most active

Strombolian style pyroclastic flows; lava flows 10/3/18 ash 6 km high

did the earthquake trigger the volcanic eruption?

…. most likely not as volcano was active before EQ

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SIO15-18: Lecture 6 Earthquake Hazards

Compared to long faults, large earthquakes are

n shorter faults?

POPQUIZ #2

YOUR FULL NAME AND STUDENT ID# no credit if one is missing

less likely
more likely
equally likely

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

source:NOAA

Florida panhandle/

Alabama

but Georgia, Carolinas

also in path

formed in GoM
landfall 1 pm Wed

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SIO15-18: Lecture 6 Earthquake Hazards

source:NOAA

Florida panhandle/

Alabama

but Georgia, Carolinas

also in path

SIO15-18: Lecture 6 Earthquake Hazards

Sumatra-Andaman 26 Dec 2004

Mw=9.1; 10m tsunami
3rd largest EQ in 100 years
> 240,000 fatalities
in ocean, along subduction zone

Tohoku 11 Mar 2011

Mw=9.0; 40m tsunami
4th largest EQ in 100 years
< 20,000 fatalities
in ocean, along subduction zone
Fig. 6.11
Fig. 6.13

source:Wikipedia source:Wikipedia

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SIO15-18: Lecture 6 Earthquake Hazards

SIO Pier Dec 27 and Dec 29 2006

shallow-water waves (D < λ/20) particle motion elliptical deep-water waves (D > λ/2) waves do not sense bottom particle motion circular v = λ/T or v=g T/(2π)

Chapter 6 (incomplete) λ from cm to n100 m

wave height depends on

wind speed
duration of wind
fetch

SIO15-18: Lecture 6 Earthquake Hazards

Image: S. Marshak “Earth, Portrait of a Planet”

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

Fig. 6.17
caused by submarine EQs with

vertical displacement

extremely long wavelength

(200 km)

shallow-water waves -> speed

depends on water depth D

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SIO15-18: Lecture 6 Earthquake Hazards

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

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SIO15-18: Lecture 6 Earthquake Hazards

Source: NOAA

partial warning system critical components missing sporadic tsunami history poor tsunami education

Fig. 6.20

26 December 2004 Sumatra-Andaman Tsunami

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

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SIO15-18: Lecture 6 Earthquake Hazards

Predicted Heights of Japan Tsunami

Background info: 27 March 1964 Good Friday Alaska EQ 12 fatalities in Crescent City

Source: NOAA/wikipedia

Fig. 6.19

SIO15-18: Lecture 6 Earthquake Hazards 23:11

13:11 HST

17:48

21:28 PDT

04:28

Predicted Heights of Samoa Tsunami

Source: NOAA

Crescent City, CA

Mw=8.1; Mercalli intensity VI largest EQ in 2009 tsunami locally up to 14 m > 189 fatalities

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SIO15-18: Lecture 6 Earthquake Hazards

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

29 September 2009 Samoa Tsunami

Source: NOAA

watch tide calendar flee when low tide suspicious you have at least 15min flee when there was an EQ and you are within 1mi of beach you have at least 15min If you felt an EQ If EQ was distant stay away from beach for many hours!!!

Fig. 6.24

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SIO15-18: Lecture 6 Earthquake Hazards

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”