earthquake seismology and earthquake hazard introduction.pdf · geolgh7/gg09/4002 earthquake...

GEOLGH7/GG09/4002 EARTHQUAKE SEISMOLOGY AND EARTHQUAKE HAZARD

Earthquake Seismology and Earthquake Hazard

Peter Sammonds



Course detailsGH07 MSc Geophysical HazardsGEOLGG09 MSc Geoscience / Earthquake

EngineeringGEOL4002 MSci Geophysics etc.M (masters) level course

7.5-10 ECTS (PG) Half course unit (UG)


Earthquake Seismology and Earthquake HazardCourse organiserPeter Sammonds Professor of Geophysics Department of Earth SciencesOffice: Pearson Building, 2nd

Email: [email protected] website: www.es.ucl.ac.uk/people/sammonds/

Other contributorsAlan Douglas Blacknest Observatory 1 dayTim Wright COMET, Leeds University 1 day Tiziana Rossetto Civil Engineering, UCL 1 lectureClare Matthews Earth Sciences, UCL PG teacherJoanna Faure Walker Earth Sciences, UCL PG teacher


Earthquake Seismology and Earthquake HazardWorkloada) 20 Lectures 20 hrsb) 6 Self-guided tutorials 18 hrsc) 3 Analytical/computing practicals 16 hrs d) Study visit to seismological observatory 6 hrse) Earthquake hazard exercise 6 hrse) Private reading 40-50 hrsf) Practical write ups 18-27 hrsg) Revision 30 hrs

Total: 150-170 hrs

AssessmentWritten examination: 80% 2 hrs 30 minsCoursework: 20% 2/3 Practical write-upsBoth examination and coursework must be passed


Times & venuesMonday 1.00pm to 6.00pmWk1: Starting Monday 1st OctoberLectures & Practicals: 188 Tottenham Court Road, Room SB5

Computer practicals: Computer Terminal Room, 2nd flr South Wing (PIN: 25334) & Lewis Workroom, Basement Lewis

Earthquake Hazard Exercise



Blacknest trip

Compulsory exercises at BlacknestWednesday / Thursday 7th/8th November10.00 LectureHalf day visit – depart 11.30 am Paddington

Professor Alan DouglasBlacknest Seismological ObservatoryMoD, AWE Aldermaston

www.blacknest.gov.uk/



Course outline

Observational SeismologyEarthquake Waves & SeismogramsIASPEI Seismology HandbookVisit to Blacknest Observatory

Earthquake Source MechanicsSeismic Moment & SeismotectonicsEarthquake magnitude & intensitySeismometer

Theoretical SeismologySignal Processing Tutorial



Tectonics

Strain-Stress Tensors

State of Stress in the Crust

Earth Materials

Satellite Remote Sensing

Earthquake cycle deformation

Interpreting interferograms

Earthquake Hazard Exercise

Earthquake engineering

Earthquake Recurrence

Earthquake Statistics

Realistic Disaster Scenarios


Earthquake Seismology and Earthquake Hazard1. Propagation of seismic waves

Observational seismology

How to interpret a seismogram:-

analyse both old ink trace and modern digital records

analysing earth structure


Earthquake Seismology and Earthquake Hazard2. Earthquake source mechanics

Seismotectonics

Determining the earthquake focal mechanism:-

using Matlab

Seismotectonics:-

earthquake hazard assessment


Earthquake Seismology and Earthquake Hazard3. Propagation of seismic waves

Theoretical seismology

Understand elastodynamicequation:-

solutions to it tell us about the earthquake source, seismotectonics, earth structure, ground motion

( )

⎥⎥⎦

⎤

⎢⎢⎣

⎡

∂∂

∂+

∂∂∂

+∂∂

∂=

⎟⎟⎠

⎞⎜⎜⎝

⎛

⎥⎥⎦

⎤

⎢⎢⎣

⎡

∂

∂+

∂∂

+∂∂

∂∂

=

+∂∂

=∂

∂

ij

j

jj

i

ki

k

i

j

j

i

k

kij

j

ijkkijjj

ij

xxu

xxu

xxu

xu

xu

xu

x

xx

222

2

μλ

μδλ

εμεδλσ


Earthquake Seismology & Earthquake Hazard4. Earthquake faulting

Analysis of strain & stress

Observed interferogramcalculated from ERS-1 SAR images taken before and after the Izmit Earthquake


5. Earthquake source mechanics Earthquake models and scaling


Friction and fluid flow models of earthquakes:-

Slip weakening model

Rate and state models

Fractal scalingCoulomb stress model


5. Earthquake designGround motion & damageSocial & economic impact


Ground motion from wave equation

Tsunami

Shake maps

Soils and structures


6. Forecasting earthquakesEarthquake statistics


Poisson statistics

Non-Poissonian statistics

Extremal statistics

Hazard maps: practical hazard assessment

Approaches to forecasting and warning


Great Kanto Earthquake 1923• Great Kanto earthquake (Mw = 7.9; Ms = 8.2) • Occurred along the Sagami Trough in the Sagami Bay on 1 September 1923 • One of the most disastrous earthquakes in Japanese history

• Earthquake claimed 99,331 dead, 43,746 missing, and left 3.4 million homeless

• Major social consequences - systematic massacre of 6,000 Koreans & political assassinations

Refugees –Imperial Palace

Saiten Tamura


Great Kanto Earthquake 1923

JMA Intensities



Ratio of total collapse of wooden houses



Tsunami damage –Yuigahama Beach

• Tsunami height reached 12 m at Atami in Shizuoka Prefecture and 9.3 m at Aihama on the Boso Peninsula

• The tsunami struck Atami, located close to the focal region, about 5 minutes after the earthquake occurred

• Hence the tsunami was not triggered directly by the earthquake itself, but a subsequent submarine landslide

• There was no large tsunami wave inside Tokyo Bay



Lloyd’s realistic disaster scenariosUSA Windstorm, Marine Collision in Prince William Sound, North Sea- Loss of Major Complex, Aviation Collision, Satellite Risks, Political Risks, Liability Risks

Compulsory ScenariosSecond Event, Florida Windstorm, California Earthquake, New Madrid Earthquake, European Windstorm, Japanese Earthquake, Terrorism

Objective is for syndicates to estimate losses in a variety of hypothetical disaster scenarios

Wanted me to assess how realistic this scenarios was and the impacts, including a tsunami assessment



JMA Intensities: Maximum is 7

Lloyds RDS: is it realistic?


Reading listRecommended TextsShearer P M (1999) Introduction to Seismology, C.U.P.

Bolt B A (2003) Earthquake 5th edition, W H Freeman & Co., New York

Woo G (1999) The Mathematics of Natural Catastrophes, Imperial College PressAn advanced text from an unusual viewpoint, directed towards the insurance industry.

Fowler C M R (2005) The Solid Earth 2nd edition, Cambridge University PressA general introductory geophysics text

Vita-Finzi C (2002) Monitoring the Earth, TerraReadable account of active tectonics

earthquake seismology and earthquake hazard introduction.pdf · geolgh7/gg09/4002 earthquake...

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