weston observatory
DESCRIPTION
Weston Observatory. Weston Observatory is a geophysical research laboratory of the Department of Earth and Environmental Sciences at Boston College. The Observatory is located in Weston , Massachusetts, about 10 miles west of BC’s Chestnut Hill campus. Magnitude 9.0 Japan March 11, 2011. - PowerPoint PPT PresentationTRANSCRIPT
Weston Observatory
Weston Observatory is a geophysical research laboratory of the Department of Earth and Environmental Sciences at Boston College. The Observatory is located in Weston, Massachusetts, about 10 miles west of BC’s Chestnut Hill campus.
Magnitude 9.0Japan
March 11, 2011
What’s the biggest earthquake ever recorded?
(A) Japan, 2011(B) Alaska, 1964(C) Missouri, 1811(D) Chile, 1960
M 9.0M 9.2M 7.5M 9.5
Largest Earthquakes Ever Recorded
1. Chile, 1960 Magnitude 9.5
3. Sumatra, 2004 Magnitude 9.1
2. Alaska, 1964 Magnitude 9.2 4. Japan, 2011
Magnitude 9.0
5. Kamchatka, 1952 Magnitude 9.0
Magnitude 9.0Near East Coast of Honshu, Japan
Magnitude 6.5 – Bali Sea
Magnitude 6.5 - Japan Aftershock
Where do most earthquakes occur?(A) Australia(B) Around the edges of the Atlantic Ocean(C) Around the edges of the Pacific Ocean(D) Antarctica
Earthquakes
Plate Tectonics
Earthquakes correlated with:
* Mid-Ocean Ridges
* Fracture Zones
* Ocean Trenches
1980-2001 (NEIC, M≥5)
How different is the rate of earthquakes in the Eastern U.S. vs. in California?Each year California has about ____ times the number of earthquakes that the Eastern U.S. has.
(A) 20 (B) 1000 (C) 5 (D) 300
Magnitude 3.5 and Greater, 1974-2003
EUS States: 264
California: 4895 (19 times as many earthquakes as EUS)
Where is the closest plate boundary to Boston?(A) California(B) Mid-Atlantic Ridge(C) Caribbean-North American plate boundary (D) Pacific-North American plate boundary
Where was the largest known earthquake east of the Rockies?
(A) Florida(B) Quebec(C) Missouri(D) Massachusetts
New Madrid, MO: 1811-1812 Charlevoix, Quebec: 1663
Estimated magnitudes each about 7.5From: Ebel (2011)From: Hough et al. (2000)
Where was the largest known earthquake in New England?
(A) Off the coast of southern CT(B) Off the coast of Cape Ann, MA(C) Central VT(D) Southern ME
* MLg 6.2, M 5.9
Cape Ann, MAEarthquake
November 18, 1755
Magnitude 5.9-6.2*
From: Ebel (2006)
VIVII
V
IV
VII
Woodcut illustration showing damage to Boston, MA, during the Cape Ann earthquake of November 18, 1755. Shaking was strongest northeast of Boston. The earthquake caused considerable damage in Boston, knocking down or damaging as many as 1,600 chimneys and collapsing brick walls of several buildings. Image from National Information Service for Earthquake Engineering, University of California, Berkeley.
Eastern United StatesNortheastern United States
Weston Observatory1/1/1975 - 10/11/2011
1700-2011, Magnitude 5.0-7.4USGS
Which of these cities has experienced a damaging earthquake since Europeans settled in North America?
(A) Boston(B) New York City(C) Washington, DC(D) All of the above
From: www.iris.edu
Rule of Thumb:
Building period approximately equals number of stories divided by 10.
Building Height Natural Period
1 story 0.1 seconds
2 story 0.2 seconds
5 story 0.5 seconds
10 story 1.0 seconds
20 story 2.0 seconds
30 story 3.0 seconds
50 story 5.0 seconds
SlowerShaking
What should you do if you felt strong earthquake shaking:
• Right now?• If you are in bed?• If you are eating in Lyons?• If you are outside in the
quad?