THE NORTHRIDGE EARTHQUAKE 4:30 am JANUARY 17, 1994 San Fernando Valley, Los Angeles, California J eng F untanilla George Mason University EOS 657: Lithosphere

THE THE NORTHRIDGNORTHRIDG

E E EARTHQUAKEARTHQUAK

EE4:30 am4:30 am

JANUARY 17, 1994JANUARY 17, 1994

San Fernando Valley,San Fernando Valley,Los Angeles, Los Angeles,

CaliforniaCalifornia

JJeng eng FFuntanillauntanilla

George Mason UniversityGeorge Mason UniversityEOS 657: LithosphereEOS 657: Lithosphere

November 9, 2005November 9, 2005

SEISMOLOGICAL SETTINGSEISMOLOGICAL SETTINGEpicenter:Epicenter: 20 Miles NW of Los Angeles 20 Miles NW of Los Angeles

Beneath the San Fernando Valley Beneath the San Fernando Valley

3434◦◦12’N, 1812’N, 18◦◦32’W32’W

Focal Depth:Focal Depth: 18.4 km18.4 km

Magnitude:Magnitude: 6.7 (Ms, surface wave 6.7 (Ms, surface wave magnitude) / magnitude) /

6.7 (Mw, seismic moment 6.7 (Mw, seismic moment magnitude)magnitude)

Duration: Duration: 15 Seconds15 Seconds

Aftershocks:Aftershocks: Over 3000 of M>1.5 in the first Over 3000 of M>1.5 in the first three three week after the earthquakeweek after the earthquake

Largest is M5.9, 1 minute after the Largest is M5.9, 1 minute after the main shockmain shock

The earthquake was felt over more than 200,000 sq-km of The earthquake was felt over more than 200,000 sq-km of land area in US and Mexico.land area in US and Mexico.

Reference: [Schiff, 1995] Schiff, A. Northridge Earthquake. ASCE, NY, 1995

SEISMOLOGICAL SETTINGSEISMOLOGICAL SETTING

http://www.lafire.com/famous_fires/940117_NorthridgeEarthquake/quake/01_EQE_exsummary.htm

EARTHQUAKE IN PROGRESSEARTHQUAKE IN PROGRESS

http://www.weatherstock.com/earthquakecat3.html

MAJOR FAULTS AND EPICENTER MAJOR FAULTS AND EPICENTER IN CALIFORNIAIN CALIFORNIA

http://www.mines.utah.edu/geo/courses/UOnline/slideshow/Nor_SFer.html

FAULTS IN SAN FERNANDO VALLEYFAULTS IN SAN FERNANDO VALLEY

The initial rupture (epicenter) of the Northridge earthquake was at the blue dot, then the rupture quickly spread northward up the Newhall fault to include all of the area in purple. The rupture broke the surface at the area shown in yellow. The Newhall fault is a blind thrust, first noticed and mapped only after the earthquake.http://www.mines.utah.edu/geo/courses/UOnline/slideshow/Nor_SFer_5.html

THE FAULTTHE FAULT

The Northridge earthquake occurred at the The Northridge earthquake occurred at the intersection of several mapped faults that did intersection of several mapped faults that did not extend to the surface and was not not extend to the surface and was not mapped before the earthquake occurred. mapped before the earthquake occurred.

► Started at the southeastern corner of the fault plane and Started at the southeastern corner of the fault plane and ruptured up to the northwest for about 15 km but ruptured up to the northwest for about 15 km but no slip no slip above a depth of 8 kmabove a depth of 8 km. (if closer to the earth’s surface, more . (if closer to the earth’s surface, more severe damage might have occurred)severe damage might have occurred)

► Part of a broad system of thrust faults that result from a Part of a broad system of thrust faults that result from a 160-160-km left step in the Pacific-North American plate boundary at km left step in the Pacific-North American plate boundary at the Big Bendthe Big Bend of the San Andreas fault. of the San Andreas fault.

► The deformation was a result of the The deformation was a result of the compression associated compression associated

with the movement around the Big Bend generated by north-with the movement around the Big Bend generated by north-dipping and south-dipping sub parallel faultsdipping and south-dipping sub parallel faults, only some of , only some of which come to the surface.which come to the surface.


DEFORMATIONDEFORMATION

► The elastic strain The elastic strain caused by the caused by the earthquake earthquake deformed deformed the crust over 5000 sq the crust over 5000 sq kmkm surrounding the surrounding the epicenterepicenter

► The region was The region was lifted lifted up to 70 cmup to 70 cm and and displaced horizontallydisplaced horizontally by as much as by as much as 20 cm20 cm. .

Another view of the San Fernando Valley and Northridge rupture, this time looking southeast. Notice how the fault splays (splits) just before reaching the surface, squeezing up a wedge of mountains.

http://www.mines.utah.edu/geo/courses/UOnline/slideshow/Nor_SFer_7.html

SHAKE MAPSHAKE MAP

Northridge earthquake shake map showing the result of rupture directivity toward the north.

http://images.google.com/imgres?imgurl=http://www.bhrc.ac.ir/Bhrc/d-stgrmo/SHABAKEH/faq/files/Directivity_files/image002.jpg&imgrefurl=http://www.bhrc.ac.ir/Bhrc/d-stgrmo/SHABAKEH/faq/files/Directivity.htm&h=226&w=277&sz=13&tbnid=B-zgJ66bBkUJ:&tbnh=88&tbnw=109&hl=en&start=95&prev=/images%3Fq%3Dnorthridge%2Bearthquake%2Bpictures%26start%3D80%26svnum%3D10%26hl%3Den%26lr%3D%26sa%3DN

DAMAGES AND LOSSESDAMAGES AND LOSSES

Number of Injured:Number of Injured: 9,000+9,000+

Number of Deaths:Number of Deaths: ~~5757

Direct and Indirect Costs:Direct and Indirect Costs: ► $44 Billion in damage $44 Billion in damage ► $30 Billion received in federal and private insurance $30 Billion received in federal and private insurance

funds funds ► $800 Billion replacement value on taxable property $800 Billion replacement value on taxable property

Structural Damage (Buildings):Structural Damage (Buildings):► 25,000 Dwellings uninhabitable 25,000 Dwellings uninhabitable ► 1,600 Buildings “red tagged” unsafe to enter1,600 Buildings “red tagged” unsafe to enter► 7,300 Buildings “yellow tagged” restricted entry7,300 Buildings “yellow tagged” restricted entry► 9 Hospitals closed (2,500 beds lost) 9 Hospitals closed (2,500 beds lost) ► 9 Parking garages collapsed 9 Parking garages collapsed ► Moment steel frames suffered huge, unexpected cracks Moment steel frames suffered huge, unexpected cracks


DAMAGES AND LOSSESDAMAGES AND LOSSES

Structural Damage (Highways/ Structural Damage (Highways/ Bridges/Ports):Bridges/Ports):

► Portions of 11 major roads into Los Angeles had to close Portions of 11 major roads into Los Angeles had to close ► 2 Bridges on the I-10 Santa Monica Freeway collapsed 2 Bridges on the I-10 Santa Monica Freeway collapsed ► 3 Bridges on Route 118 Simi Valley Freeway collapsed 3 Bridges on Route 118 Simi Valley Freeway collapsed ► 2 Bridges on I-5 at the 14 interchange collapsed 2 Bridges on I-5 at the 14 interchange collapsed ► 2 Bridges (Gavin Canyon Bridges) on I-5 collapsed 2 Bridges (Gavin Canyon Bridges) on I-5 collapsed

Miscellaneous Facts:Miscellaneous Facts:► 22,000 People were left homeless 22,000 People were left homeless ► Costliest disaster in US historyCostliest disaster in US history


POST EARTHQUAKE RESPONSEPOST EARTHQUAKE RESPONSE

► POWER SYSTEMSPOWER SYSTEMS Longest disruption lasted about 3 hoursLongest disruption lasted about 3 hours 93% was restored within 24 hours93% was restored within 24 hours 99.5% restored in 72 hours99.5% restored in 72 hours Total Direct losses: $138M to LA Dept of Water and Power, Total Direct losses: $138M to LA Dept of Water and Power,

$45M to Southern California Edison$45M to Southern California Edison More stringent equipment seismic specifications were adopted More stringent equipment seismic specifications were adopted

and expanded the use of composite materials was planned.and expanded the use of composite materials was planned.

► WATER SYSTEMSWATER SYSTEMS Over 30 tanks were damagedOver 30 tanks were damaged Several communities were without water for about two weeks Several communities were without water for about two weeks

and boiling water for consumption was in effect and boiling water for consumption was in effect Water system facilities performed well because they were Water system facilities performed well because they were

seismically upgraded from the 1971 San Fernando earthquake.seismically upgraded from the 1971 San Fernando earthquake.


POST EARTHQUAKE RESPONSEPOST EARTHQUAKE RESPONSE► WASTEWATER SYSTEMWASTEWATER SYSTEM

Sewer pipeline damage was not obvious immediately unlike in the Sewer pipeline damage was not obvious immediately unlike in the past.past.

The loss of power resulted to disruption in the operation The loss of power resulted to disruption in the operation treatment plants and sewer pumping plantstreatment plants and sewer pumping plants

Standby generator and sewer bypass prevented any sewage from Standby generator and sewer bypass prevented any sewage from spilling.spilling.

► COMMUNICATION SYSTEMSCOMMUNICATION SYSTEMS Five switch failures at four sites of local telecommunication Five switch failures at four sites of local telecommunication

infrastructure due to loss of power.infrastructure due to loss of power. Cable spans had minimal physical damageCable spans had minimal physical damage 911 continued to operate during and after the main shock911 continued to operate during and after the main shock Damage and interruption of cellular carriers was minimal.Damage and interruption of cellular carriers was minimal. USGS scientists analyze and broadcast infornmation to public and USGS scientists analyze and broadcast infornmation to public and

maitained steady flow of communiationmaitained steady flow of communiation Radio and television played a big role in informing the public on Radio and television played a big role in informing the public on

emergency response and recovery act.emergency response and recovery act.


POST EARTHQUAKE RESPONSEPOST EARTHQUAKE RESPONSE► BRIDGES AND ROADWAYSBRIDGES AND ROADWAYS

Seven bridges sustained severe damage. (Gavin Canyon on I5, 14/5 Seven bridges sustained severe damage. (Gavin Canyon on I5, 14/5 Interstate, Route 18 west of Route 405, Sta Monica Freeway etc)Interstate, Route 18 west of Route 405, Sta Monica Freeway etc)

► RAILROADSRAILROADS A 62-car Southern Pacific freight train traveling through Northridge was A 62-car Southern Pacific freight train traveling through Northridge was

derailed, spilling 8K gallons of sulfuric acid and 2K gallons of diesel fuel derailed, spilling 8K gallons of sulfuric acid and 2K gallons of diesel fuel from the engine (operator reported seeing a 3-foot high ripple in the from the engine (operator reported seeing a 3-foot high ripple in the track). Cleared by Jan. 21track). Cleared by Jan. 21stst..

Were well prepared and response procedures have been well rehearsedWere well prepared and response procedures have been well rehearsed No personnel problems, no overtimeNo personnel problems, no overtime

► PORTSPORTS Light compared to damage in Loma Prieta and Kobe earthquakes but Light compared to damage in Loma Prieta and Kobe earthquakes but

improvements to the port’s emergency response plans has been improvements to the port’s emergency response plans has been adopted.adopted.



► AIRPORTSAIRPORTS Van Nuys, Los Angeles Int’l and Burbank airports had Van Nuys, Los Angeles Int’l and Burbank airports had

significant ground shaking and were closed to traffic up to 1 ½ significant ground shaking and were closed to traffic up to 1 ½ hours.hours.

Standards for improving emergency power generators and Standards for improving emergency power generators and support systems was implemented because it can severely support systems was implemented because it can severely impact operations and be very disruptive.impact operations and be very disruptive.

► TRANSPORTATION SYSTEMTRANSPORTATION SYSTEM Major damage to transportation facilities was confined to four Major damage to transportation facilities was confined to four

major highways major highways Detours were in place, ridesharing and new carpool lanes were Detours were in place, ridesharing and new carpool lanes were

createdcreated



► HOSPITALSHOSPITALS 9 were closed, 6 were evacuated, 1,000 patients were 9 were closed, 6 were evacuated, 1,000 patients were

evacuated evacuated 1st 5-days: 10,000 were treated, 1,300 was admitted, 220 1st 5-days: 10,000 were treated, 1,300 was admitted, 220

were in critical, ~57 deathswere in critical, ~57 deaths LA County Medical Center: 1,750 intensive care beds, 216 LA County Medical Center: 1,750 intensive care beds, 216

unoccupiedunoccupied St. Johns Hospital in Sta Monica was closed for 3 monthsSt. Johns Hospital in Sta Monica was closed for 3 months

► FIRE DEPARTMENTFIRE DEPARTMENT 1973, LAFD adopted Earthquake Emergency Operational 1973, LAFD adopted Earthquake Emergency Operational

PlanPlan 788 on-duty788 on-duty 35 stations: 1 closed for 1 month for roof repair, 1 out-of-35 stations: 1 closed for 1 month for roof repair, 1 out-of-

service for 6 months, 1 condemned and demolishedservice for 6 months, 1 condemned and demolished


TECHNOLOGY IN PLACETECHNOLOGY IN PLACE

► REAL-TIME SEISMOLOGYREAL-TIME SEISMOLOGY USGC and SCEC installed more instruments in place for USGC and SCEC installed more instruments in place for

monitoringmonitoring

► LOSS ESTIMATIONLOSS ESTIMATION Database managementDatabase management

► GPSGPS SCEC, USGS and NASASCEC, USGS and NASA

► GIS and INTERNETGIS and INTERNET Maps and illustrations for scientists, emergency personnel and Maps and illustrations for scientists, emergency personnel and

mediamedia

► AERIAL AND SATELLITE-BASED MONITORING AERIAL AND SATELLITE-BASED MONITORING SYSTEMSSYSTEMS Monitors geological changes (pre and post) as a source for damage Monitors geological changes (pre and post) as a source for damage

assessmentassessmentReference: [Schiff, 1995] Schiff, A. Northridge Earthquake. ASCE, NY, 1995

► USGS USGS – U.S. Geological Society– U.S. Geological Society At Caltech was the center of information processing and maintained At Caltech was the center of information processing and maintained

communication with emergency response agenciescommunication with emergency response agencies► NEHRP NEHRP – National Earthquake Hazards – National Earthquake Hazards

Reduction Program Reduction Program (March 14, 1977)(March 14, 1977) Assigned 84 specific tasks for 2 years oriented towards a timely, Assigned 84 specific tasks for 2 years oriented towards a timely,

effective response for future earthquakes.effective response for future earthquakes. Tasked to perform post earthquake investigation funded by Tasked to perform post earthquake investigation funded by

Emergency Disaster Appropriation by CongressEmergency Disaster Appropriation by Congress► SCECSCEC – Southern California Earthquake – Southern California Earthquake

Center Center (1991)(1991) Focus on applying earth science to earthquake-hazards destruction.Focus on applying earth science to earthquake-hazards destruction.

► FEMAFEMA – Federal Emergency Management – Federal Emergency Management AgencyAgency Coordinated evacuation and emergency response system.Coordinated evacuation and emergency response system.

AGENCIES’ COORDINATED EFFORTAGENCIES’ COORDINATED EFFORT(During and After)(During and After)

http://pubs.usgs.gov/of/1996/ofr-96-0263/

Undersized footings and columns, inadequate column to beam connections, lack of diagonal bracing Pre-cast double T collapse - inadequate attachment This buckling shows the structural failure produced by high vertical

acceleration.

DAMAGE ASSESSMENTDAMAGE ASSESSMENT

“Bending" and partial collapse of the outer wall of a 2500-car-capacity parking structure due to intense shaking of the Northridge earthquake

Both gas and water pipes burst beneath creating this bizarre

and destructive combination of fire and water. A few cases of cynical humor among shattered buildings. Building failure. Wrong size beams, not enough cross bracing.

http://images.google.com/images?q=northridge+earthquake+pictures&hl=en&lr=&sa=N&tab=ii&oi=imagest

DAMAGE ASSESSMENTDAMAGE ASSESSMENT

Aerial view of Interstate 5 collapse at Gavin Canyon

Bridge 53

Interstate 5

http://nisee.berkeley.edu/northridge_images.html

Intersection of Highway 14 and Interstate 5

California California EarthquakesEarthquakes

1906 to Present1906 to Present

San Francisco, 1906San Francisco, 1906

http://images.google.com/imgres?imgurl=http://www.goldenstatemuseum.org/map/eanorthridge.jpg&imgrefurl=http://www.goldenstatemuseum.org/genorthridge.htm&h=375&w=324&sz=22&tbnid=DnMbLIhraZcJ:&tbnh=118&tbnw=101&hl=en&start=5&prev=/images%3Fq%3Dnorthridge%2Bearthquake%2Bpictures%26svnum%3D10%26hl%3Den%26lr%3D%26sa%3DN

One of the most significant earthquakes of all time, it caused a 3-day fire, leaving approximately 3,000 dead and 250,000 homeless. It was felt as far north as Coos Bay, Oregon, and as far south as Los Angeles.

Deaths: 3,000Injuries: unknownDamage: $500M

Imperial Valley, 1915Imperial Valley, 1915


Two short, 11 second, quakes caused extensive damage.

Magnitude: 6.1 Deaths: 6Damage: $1M

San Jacinto, 1918San Jacinto, 1918


This quake caused many landslides, several streams to change course, and the temperature of hot springs to change

Magnitude: 6.8 Deaths: 1Injuries: 10

Santa Barbara, 1925Santa Barbara, 1925


This earthquake leveled 36 blocks of downtown Santa Barbara and compelled legislators to improve building standards.

Magnitude: 6.3 Deaths: 13Damage: $6.5M

Long Beach, 1933Long Beach, 1933


This quake, which damaged many schools, led to the establishment of state standards for safer school design.

Magnitude: 6.3 Deaths: 115Injuries: 600Damage: $50M



This quake damaged irrigation systems, bent railway lines, destroyed bridges, and shifted the earth by 6 feet.


Kern County, 1952Kern County, 1952


This deep quake was among the largest in Southern California, causing widespread damage with over 20 aftershocks.


Parkfield, 1966Parkfield, 1966


Striking a sparsely populated area, this quake caused little damage. Parkfield is now a center for earthquake prediction research.

Magnitude: 6.0 Deaths: 0

San Fernando, 1971San Fernando, 1971


A major quake causing extensive property damage in the Los Angeles area.

Deaths: 3,000Injuries: unknownDamage: $500M

Point Mugu, 1973Point Mugu, 1973


This earthquake destroyed powerlines, but caused little other damage.




This quake produced a slip in the earth of about 20 inches.


Owens Valley, 1980Owens Valley, 1980


A quake followed by three main aftershocks of magnitude 6.0-6.1 struck this sparsely populated area


Coalinga, 1983Coalinga, 1983


This quake destroyed over 800 homes and other buildings, and was felt as far away as Los Angeles and western Nevada.

Magnitude: 6.4 Deaths: 0Injuries: 47Damage: $31

Oceanside, 1986Oceanside, 1986


Over 50 buildings were damaged in this quake, which was centered offshore beneath the Pacific Ocean.

Magnitude: 5.3 Deaths: 1Injuries: 28Damage: $0.72M

Whittier Narrows, 1987Whittier Narrows, 1987


Two quakes, three days apart, occurred on a previously unknown fault east of Los Angeles and caused severe damage

Magnitude: 5.3/5.9

Deaths: 8Injuries: 200Damage: $358M

Loma Prieta, 1989Loma Prieta, 1989


A significant quake, this caused over a half billion dollars worth of property damage.

Magnitude: 7.1 Deaths: 63Injuries: 3,757Damage: $5.9B

Sierra Madre, 1991Sierra Madre, 1991


This earthquake caused extensive rockslides, but no surface rupture


Big Bear, 1992Big Bear, 1992


This quake caused no surface fracture, but triggered many landslides.


Cape Mendocino, 1992Cape Mendocino, 1992


This earthquake was followed by aftershocks registering up to 6.6 magnitude.


Northridge, 1994Northridge, 1994


This quake damaged over 25,000 buildings, closed 11 major roads, and left 22,000 people homeless.

Magnitude: 6.7 Deaths: 57 Injuries: 9,000Damage: $44B

Hector Mine, 1999Hector Mine, 1999


This quake, in a remote area of the Mojave Desert, created a 25-mile long surface rupture along what had been classified as an inactive fault.

Magnitude: 7.1 Deaths: 0 Injuries: 0

Thank you!Thank you!

http://quake.wr.usgs.gov/recenteqs/Maps/Los_Angeles.html

To view recent earthquakes in Los Angeles, California:

Documents

THE NORTHRIDGE EARTHQUAKE 4:30 am JANUARY 17, 1994 San Fernando Valley, Los Angeles, California J eng F untanilla George Mason University EOS 657: Lithosphere