Major earthquakes around the world

Tōhoku
earthquake
JAPAN 2011
GYANENDRA PRAKASH
13526015
(STRUCTURAL DYNAMICS)

INTRODUCTION
 Also known as the GREAT EAST JAPAN
EARTHQUAKE and the 3.11
EARTHQUAKE.
 It is the most powerful EQ ever recorded in
JAPAN and fifth most powerful in the world
since 1900.
 Led to tsunami waves, flooding, landslides,
fires, building & infrastructure damage,
nuclear incidents, etc.

EQ CHARACTERISTICS
TYPE UNDERSEA MEGATHRUST
MOMENT MAGNITUDE 9.0
SEISMIC MOMENT 0.332×1030 dyne-cm
ENERGY RELEASED 1.9 ± 0.5×1017 joules
TIME 14:46:23JST (05:46 GMT)
DAY/DATE FRIDAY/11-03-2011
EPICENTER 70KM (43.5mi) east of Tōhoku
38.322°N 142.369°E
HYPOCENTER 30KM (18.6 mi) underwater
DURATION 6 minutes
MAX. INTENSITY IX
PGA 2.93g (USGS)
MAX. TSUNAMI RUNUP
HEIGHT
37.88 m at MIYAKO

DAMAGE & EFFECTS
ATLEAST
 15,703 people killed
 4,647 missing, 5,314 injured and 130,927
displaced
 1,800 houses destroyed when dam failed in
FUKUSHIMA
 332,395 buildings, 2,126 roads, 56 bridges and
26 railways destroyed or damaged by EQ and
TSUNAMI.

 The tsunami caused nuclear accidents,
primarily the level 7 meltdowns at three
reactors in the Fukushima Daiichi Nuclear
Power Plant.
 Matsushima Air Field of the Japan Self-
Defense Force in Miyagi Prefecture was struck
by the tsunami, flooding the base and resulting
in damage to all 18 Mitsubishi F-2 fighter jets of
the 21st Fighter Training Squadron.
 US$235 billion economic losses had been
experienced as per the World Bank's estimate
making it the costliest natural disaster in world
history.

GEOLOGY & TECTONICS
 This earthquake occurred where the Pacific
Plate is subducting under the plate beneath
northern Honshu.
 The Pacific plate, which moves at a rate of 8
to 9 cm (3.1 to 3.5 in) per year, dips under
Honshu's underlying plate building large
amounts of elastic energy. This motion
pushes the upper plate down until the
accumulated stress causes a seismic slip-rupture
event.

FOCAL MECHANISM
 STRIKE= 193°
 DIP= 14°
 RAKE= 81°
(JMA epicenter
considered)

SLIP DISTRIBUTION
 The largest asperity
developed near the
epicenter at 5-25 km
in depth (Asperity I),
one asperity located
in the deep
subduction zone
beneath the
hypocenter at about
45 km in depth
(Asperity II).

 The other two secondary asperities
occurred in the north and south from the
hypocenter and both were centered at
about 10 km in depth (Asperity III and
Asperity IV).
 The slip of the largest asperity is over 30 m
with a predominantely reverse motion and
covers a very large area of about 160x120
km2. The slips of asperity II, III and IV are
smaller and are about 20 m in average.

RUPTURE PROCESS
 At the beginning,the
rupture velocity near
the hypocenter was
initially about 1.0
km/s.
 But it increased
rapidly to 5.3 km/s at
shallow part
(Asperity I) after
about 45 second.

 During 45 to 60 second, the rupture looked
like over the velocity of shear wave that
became a supershear rupture. Almost at the
same period, the rupture propagated to the
north also found a supershear rupture
behavior between 75 and 90 second.
 The rupture velocities rapidly decreased to
about 0.2-0.5 km/s and didn’t indicate
significant change in both the north and
south.
 The rupture front almost stopped until about
165 second.

 After 160 seconds, the rupture front began
to move south in the shallow subduction
zone along the Japan Trench with a rupture
velocity of approximately 2.0 km/s until the
end of the rupture.

MOMENT RATE FUNCTION
 0-40 seconds is
related to the
occurrence of the
rupture nucleation.
 40-90 seconds
includes the growth of
the biggest asperity
(Asperity I) at shallow
part above the
hypocenter.

 the deep part of the fault began to rupture
between about 100 and 160 seconds,
resulting in the deep asperity (Asperity II)
beneath the hypocenter.
 The shallow portion of the fault began to slip
toward the north (Asperity III) and south after
160 seconds.
 The last release of seismic energy after about
180 to 240 seconds was caused by the slip
that ruptured to the southern area along the
Japan Trench (Asperity IV).
 The overall duration time of the main rupture
was about 240 seconds.

FORESHOCKS & AFTERSHOCKS
 7 foreshocks and 10,583 aftershocks have
been experienced till now.
 The first major foreshock was a
7.2 MW event on 9 March, approximately
40 km (25 mi) from the epicenter of the 11
March earthquake, with another three on
the same day in excess of 6.0 MW.
 Over eight hundred aftershocks of
magnitude 4.5 MW or greater have
occurred since the initial quake.

INTENSITY
 North-eastern
part of
Honshu
was
severely
affected
(based on
JMA
scale).

TSUNAMI
 The earthquake
triggered
powerful tsunami
waves that
reached heights of
up to 37.88 metres
in Miyako in
Tōhoku's Iwate
Prefecture, and
which, in the
Sendai area,
travelled up to
10 km inland.

TSUNAMI HEIGHTS OBSERVED
AT DIFFERENT LOCATIONS

GEOPHYSICAL EFFECTS
 The earthquake moved Honshu 2.4 m (8 ft)
east.
 The Earth's axis shifted by estimates of
between 10 cm (4 in) and 25 cm (10 in).
 The speed of the Earth's rotation increased,
shortening the day by 1.8 microseconds
due to the redistribution of Earth's mass.

Major earthquakes around the world

 Over 18,600 persons are
reported to be dead and
over 167,000 injured.
 The estimated economic
loss due to this quake is
placed at around
Rs.22,000 Crores.

Kobe Earthquake1995
JAPAN
Presented by
Vijay kumar & Ahmed Bilal
M.Tech. Str Dyn
E No-135260 - 31 & 04

At 05:46 a.m JST,On Tuesday 17 Jan 1995, A magnitude-7.2(JMA)
Earthquake Struck Kobe region of South-Central Japan.
Kobe is 20 km from quake center

Where did it
happen?
Epicenter was located in the
Akashi strait north of Awaji Island
in Osaka Bay some 20km from
Kobe city. The Focus was 22km
beneath the Nojima Fault.
Akashi Strait
Osaka Bay

Why did it happen?
Kobe lies on the Nojima Fault,
above a destructive plate margin.
Here the heavier, oceanic philipine
plate is forced under the lighter
continental eurasian plate. Sudden
movement of the fault caused this
major earthquake.
Nojima
Fault
Philipine plate subducted beneath the Eurasian plate

How it happened?
The earthquake
generated along the
intersection of
the Nojima fault with
the Suma fault, 16
kilometres below the
Akashi strait, 20
kilometres to the west of
the city.
The main shake was
preceded by a series of
weak trembles,
registered only by the
seismometer in Osaka,
then for 14 to 20
seconds earth trembled
reaching a magnitude of
7.2 after Richter (6.9
according to the
Japanese intensity scale
- shindo,

Fault Plane/Fault Model
Focal Mechanism
Solution
Epicenter
Fig.1. Fault model of Yoshida et al. (1996) for the 1995 Kobe earthquake. Two rectangles represent the surface projections of the
fault segments and thick lines indicate their shallower sides. The solid star with a focal mechanism solution is the epicenter of the
main shock determined by Katao et al. (1997), and gray lines are active fault traces, after KOKETSU et al. 1998.

Why Japan has large potential for Earthquakes ??
1500 EQs/Year
1. Tokyo is situated on Japan’s main Honshu island which in turn sits at the
intersection of three continental plates, the Eurasian, Pacific and Philippine
Sea plates, which are slowly grinding against each other, building up
enormous seismic pressure. Most of the largest and strongest earthquakes in
Japan are caused by subduction of the Philippine Sea Plate or Pacific Plate,
with mechanisms that involve either energy released within the subducting
plate or the accumulation and sudden release of stress in the overlying plate.
2. Japan lies along the Pacific Ring of Fire, a narrow zone around the Pacific
Ocean where a large chunk of Earth's earthquakes and volcanic eruptions
occur. Roughly 90 percent of all the world's earthquakes and 80 percent of the
largest ones strike along the Ring of Fire.
3. Japan accounts for about 20 per cent of the world's earthquakes of magnitude
six or greater and on average, an earthquake occurs there every five minutes.

Earthquake Details
Date-Time Tuesday, January 17, 1995 at 20:46:52 GMT at epicenter.
Epicenter Location 3 4 . 5 8 ° N (Latitude), 135.01°E(Longitude),Located in the Akashi
strait north of Awaji Island some 20km from Kobe city.
Focal depth 22 km (13.67 miles) set by location program (Depth of Focus)
Fault Descriptions Nojima Fault (Length = 23 km, Width = 13km) ( right-lateral
strike-slip fault with a reverse component present at destructive
plate boundary)
Location
Uncertainty
horizontal +/- 3.4 km (2.1 miles); depth fixed by location program
It was an Intra-plate inland shallow earthquake.
Magnitude
ML=6.9 (on Richter Scale) and ML=7.2 (Japan Meteorological
Agency Scale)
Maximum Intensity VII (Local)

Maximum Surface
Displacements
1-1.5 m right-lateral, 1.7m horizontal and 1 m vertical (observed)
Seismic Rupture
Length
Between 30km to 50km long and 15 km wide (bilateral rupture
from the hypocenter, (Pitarka et al., 1995; Kikuchi, 1999)
Seismic Moment 2.5x1026 dyne-cm (Mw 6.9) with a source duration of 6 to 10
seconds (Kikuchi, 1995)
Human Loss 6000 deaths, 30000 injuries, 300000 homeless
Economic Loss 200 billion dollars (estimated)
Infrastructure
Damaged
150000 Buildings Damaged, Many roadways,Bridges destroyed.
Peak Ground
Acceleration
0.5g to 0.8g (10 sites estimation)
Peak Ground
Velocity
50-175 cm/s
Duration of
Rupture and
Faulting
20 Seconds
Foreshocks and
Aftershocks
Four foreshocks, beginning with the largest (Mj 3.7) at 18:28 on
the previous day. Within five weeks, about 50 aftershocks at Mj
4.0 or greater were observed.

Instrumental
Intensity
According to Japanese
Standards, Highest level
7 on the scale
constructed by the
Japan Meteorological
Agency (JMA) occurred
in Kobe.

Isoseismal map depicting regions of strong shaking

Peak Ground
Acceleration
Max Recorded = 0.8g

Peak Ground
Velocity
Max Reached= 175cm/s

Uncertainty
Decorated
Bare
Other Shake Maps Provided by US Geological Survey

Earthquake Effects
The aftermath of the Great Hanshin earthquake can be divided into primary and
secondary effects.
The primary effects included the destruction of 150,000
buildings, the collapse of 1 km of the Hanshin Expressway,
the destruction of 120 of the 150 quays in the port of Kobe,
and fires which took over large portions of the city.
Secondary effects included some disruption of the
electricity supply. Residents of Kobe were also afraid to
return home because of the aftershocks that lasted several
days (74 of which were strong enough to be felt).

Economic Impact
• The Great Hanshin earthquake caused over ten trillion yen
($102.5 billion) in damage, or 2.5% of Japan’s GDP at the time.
• Most of the losses were completely uninsured, as only 3% of
property in the Kobe area was covered by earthquake insurance,
as compared to 16% in Tokyo.
• The earthquake destroyed most of the facilities of what were then
the world’s 6th largest container port and the source of nearly 40%
of Kobe’s industrial output.
• The magnitude of the earthquake alone caused a major decline in
Japanese stock markets, with the Nikkei 225 index plunging by
1,025 points on the day following the earthquake.

Failure of the first (soft)storey caused partial collapse of upper stories

Hanshin(Kobe) Expressway suffered severe
damage
Ten spans of the Hanshin
Expressway Route 43 in
three distinct locations in
Kobe and Nishinomiya were
completely toppled over,
blocking a key link that
carried 40% of Osaka-Kobe
road traffic. About half of the
elevated expressway’s piers
were damaged in some way.
Cause: Severe Liquefaction due to Strong Ground
Motion

Damage to highways and subways : Kobe Expressway

Leaning Sakagami Building．
(Feb. 1995)

Mid-story collapse, Kobe
earthquake

Ports in Kobe
Damaged quay walls and
port facilities on Rokko
Island. Quay walls have
been pushed outward by 2
to 3 meters with 3 to 4
meters deep depressed
areas called grabens
forming behind the walls,
Kobe 1995

Lateral displacement of a quay wall on Port Island, Kobe 1995

Fractured Road, Japan
 A crane and several
construction vehicles
lay toppled on a
fractured road in Kobe,
Japan, after a 7.2-
magnitude temblor
shook the quake-prone
country. The Great
Hanshin Earthquake
Disaster of 1995 was
one of the worst in
Japan’s history, killing
6,433 people and
causing more than
$100 billion in
damages.

Twisted Railroad,
Japan
A steel-fortified railroad lies
twisted like a toy after a 7.2-
magnitude earthquake
rocked Kobe, Japan, in
1995. The earthquake was
the biggest to hit Japan in
47 years and shook the city
for 20 seconds.

Lateral spreading caused 1.2-2 meter drop of paved surface
and local flooding, Kobe 1995.

Retaining wall damage and lateral spreading, Kobe 1995

Damages to bridges that cross rivers and other bodies of water due to
liquefaction during Kobe Earthquake.
Note: Liquefaction only occurs in saturated soil, its effects are most
commonly observed in low-lying areas near bodies of water such
as rivers, lakes, bays, and oceans.

Liquefaction induced soil movements pushed the foundations out of
place to the point where bridge spans loose support (above) or are
compressed to the point of buckling during Kobe Earthquake.

For Further Detailed Information
• http://earthquake.usgs.gov/earthquakes/world/events/1995_01_16.php [USGS Link]
• www.terrapub.co.jp/journals/EPS/pdf/5010/50100803.pdf
• http://historyofgeology.fieldofscience.com/2011/01/17-january-1995-great-kobe-earthquake.html
• http://www.ce.washington.edu/~liquefaction/html/where/where1.html [Pictures Link]
• http://www.telegraph.co.uk/news/worldnews/asia/japan/8375788/Japan-earthquake-what-causes-them.
html
• http://www.geerassociation.org/GEER_Post%20EQ%20Reports/Kobe_1995/ch2-6.html
[Strong Ground Motion Reports]
Website Links
Reference Books & Papers
• A fault model of the 1995 Kobe earthquake derived from the GPS data on the Akashi
Kaikyo Bridge and other datasets: Kazuki Koketsu, Shingo Yoshida, and Hiromichi
Higashihara, Earthquake Research Institute, University of Tokyo, Bunkyo-ku, Tokyo ,Japan.
• National Institute of Standards and Technology Special Publication 901. The January
17,1995 Kobe Earthquake ,Performance of Structures.
• Geotechnical Reconnaissance of the Effects of the January 17, 1995 Hyogoken-Nanbu
Earthquake, Japan, Report No. UCB/EERC-95/01 Earthquake Engineering Research Center
College of Engineering, University of California at Berkeley, United States of America.

1897 ASSAM EARTHQUAKE
Presented By:
DHANASHREE BANKAR
13526009
DEPARTMENT OF EARTHQUAKE ENGINEERING
INDIAN INSTITTE OF TECHNOLOGY ROORKEE
ROORKEE
Submitted to :
Dr. M. L.
Sharma

INTRODUCTION
 NORTH-EASTERN REGION- EARTHQUAKE
PRONE REGION
 ZONE V
 INDIAN PLATE DIVING IN EURASIAN PLATE
 STATE IS UNDERLAIN BY SEVERAL THRUST
(MBT, MCT, HFF AND NAGA THRUST)
 TWO MAJOR EARTHQUAKES OF MAGNITUDE
8.7 AND 8.6 OCCURRED IN 1897 AND 1950
RESPECTIVELY.

1897 ASSAM EARTHQUAKE
 DATE- JUNE 12, 1897
 TIME- 5:11 PM
 LOCATION- RANGJOLI, ASSAM
 LATTITUDE- 25.5N LONGITUTUDE
91.00E
 MAGNITUDE- 8.7(RICHTER SCALE)
 MOMENT MAGNITUDE- 8
 EPICENTRE- 14 KM ESE OF
SANGSIT (MEGHALAYA)

TECTONICS OF EARTHQUAKE
 SOUTH-SOUTH-WEST DIPPING
REVERSE OF OLDHAM FAULT
 CHEDRANG AND SAMIN FAULT
 MINIMUM DISPLACEMENT ON THE
MAIN FAULT-11M
 AREA OF SLIP EXTENDED 110 KM
ALONG THE SLIP AND 9-45 KM
BELOW THE SURFACE WITH RAKE
ANGLE OF 760

PLATEAU POP-UP
 STRESS DROP IMPLIED BY
RUPTURE GEOMETRY AND FAULT
SLIP OF 18+7m, EXPLAINS
OBSERVED EPICENTRAL
ACCELERATIONS EXCEEDING 1 g
VERTICALLY, AND SURFACE
VELOCITIES EXCEEDING 3 m/s

DAMAGES
 LOSS OF LIFE- 1542 KILLED AND HUNDRED’S
MORE HURT
 LOSS OF PROPERTY:- 150000 SQ.MILES OF
MASONARY BUILDINGS WERE RUINED
 DAMAGE EXTENDED TO 250000 SQ.MILES
FROM BURMA TO NEW DELHI
 IN NORTH GUWAHATI, 561 AFTERSHOCKS
WERE FELT TILL THE END OF 15TH JUNE

 IN SHILLONG
(1) ALL THE STONE BUILDINGS WERE COLLAPSED AND ABOUT
HALF THE EKRABUILT HOUSES WERE RUINED
(2) PLANK HOUSES WERE UNTOUCHED
(3) WATER BRUST THE BOUNDS OF THE LAKE MAKING THEM
ABSOLUTELY DRY
(4) SULPHURY SMELL IN THE AIR COMING OUT OF THE
FISSURES WAS FELT
FIG.EKRABUILT HOUSES
COLLAPSED

FIG.SHILLONG CHRUCH AFTER EARTHQUAKE

 IN GOALPARA
(1) THE EARTHQUAKE WAS ACCOMPANIED BY A TIDAL WAVE 10
FEET HIGH WHICH DESTROYED THE BAZAAR AND ALL THE
PAKKA BUILDINGS.
(2) INNUMERABLE JETS OF WATER LIKE FOUNTAINS SPOUTED
UPTO HEIGHTS VARYING 18 INCHES TO 4 FEET WERE
INSTANTLY CREATED ON THE GROUND
(3) IRON BRIDGES OF JOLDOBAAND KRISHNAI WERE BROKEN.
(4) FISSURES AND SANDVENTS OCCURRED UNIVERSALLY
THROUGHOUT GOALPARA . A FEW WERE SEEN IN LAKHIMPUR
AND IN SIBSAGAR.
FIG.ROWARI SANDVENT

 IN GUWAHATI
(1) IN GUWAHATI RIVER BRAHMAPUTRA ROSE 7.6 FEET AND
NEAR THE BANKS FLOWED UPSTREAM. IT ALSO REVERSED
ITS DIRECTION DURING THE SHOCK.
(2) SPRINGS OF WATER WITH VERY FINE SAND WERE
OBSERVED.
(3) THE RAILWAY LINES WERE DISAPPEARED. RAILS WERE
BENT TERRIBLY AT THE RANGAPARA OF TEZPUR-BALIPARA
TRAMWAY

FIG.UNDULATIONS FORMED
ON GROUND SURFACE

CONSTRUCTION
PRACTICES IN
NORTH-EAST
ASSAM TYPE
HOUSES (IKRA
HOUSES)
THATCH
HOUSES

IKRA HOUSES
 IKRA HOUSES ARE SINGLE STOREY STRUCTURES
CONSISTING OF BRICK OR STONE WALLS UPTO
ABOUT 1M ABOVE THE PLINTH
 THIS MASONARY SUPPORT THE WALLS
CONSISTING OF BAMBOO WOVEN TOGETHER
WITH A WOODEN FRAME AND PLASTERED WITH
CEMENT OR MUD PLASTER
 THE ROOF GENERALLY CONSISTS OF GI SHEETS
SUPPORTED ON WOOD/BAMBOO TRUSSES
 BAMBOO SUPERSTRUCTURE IS CONNECTED TO
THE MASONARY FOUNDATION WALLS USING
STEEL ANGLES AND FLATS WITH BOLTS AND
NAILS.

 AS BAMBOO IS VERY FLEXIBLE MATERIAL AND
ALSO LIGHT WEIGHT MATERIAL, THE SEISMIC
FORCE IS VERY LESS COMPARED TO MODERN
HOUSING SYSTEM. SEISMIC FORCE ON BAMBOO
HOUSING SYSTEM IS 12.97% AND 11.72% OF
REINFORCED BRICK MASONARY AND CONFINED
BRICK MASONARY SYSTEM RESPECTIVELY.
140
120
100
80
60
40
20
0
Ikra housing systemReinforced masonary Confined masonary
FIG. SEISMIC FORCES ON DIFFERENT HOUSING SYSTEMS

CONCLUSION
BAMBOO IS USED AS MAIN
STRUCTURAL COMPONENT IN
ASSAM BECAUSE BAMBOO IS
DUCTILE MATERIAL AND ITS
PERFORMANCE IS IMPROVED
UNDER EARTHQUAKE EVENT

Major earthquakes around the world

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