Lecture 1

Earthquakes, global tectonics and man

Motivations for studying earthquakes

It is the legitimate ambition of every properly constituted geologist to see a glacier,witness an eruptionand feel an earthquake.

G.K. Gilbert, in D.S. Jordan (ed.), The Investigation of the California Earthquake of 1906, 1907

The glacier is always ready, awaiting his visit;the eruption has a course to run, and alacrity only is needed to catch its more important phases;but the earthquake, unheralded and brief, may elude him through his entire lifetime.

It had been my fortune to experience only a single weak tremor, and I had, moreover, been tantalized by narrowly missing the great Inyo earthquake of 1872 and the Alaska earthquake of 1899.

When, therefore, I was awakened in Berkeley on the eighteenth of April last by a tumult of motions and noises, it was with unalloyed pleasure that I became aware that a vigorous earthquake was in progress. …

40,000 dead

Bam 2003 (Mw 6.8)

100,000 population

Courtesy of James Jackson

Another motivation

Loma Prieta, Ca 1989 6.9 62 urban

Northridge, Ca 1994 6.7 51 urban

Tabas, Iran 1978 7.2 11,000 v. rural

Rudbar, Iran 1990 7.3 40,000 rural

Zirkuh, Iran 1995 7.2 1,600 v. rural

Bam, Iran 2003 6.5 50,000 town

Location date magnitude deaths

number if earthquakes per century killing > 10,000 people

Courtesy of James Jackson

Areas of the World scaled according to Property Insurance Premium Income

AustraliaNew Zealand

Africa

South Africa

Hong Kong

Israel

TaiwanTurkey

Denmark

Ireland

Sweden

Germany

France

Belgium

UK

Italy

Switzerland

China

Indonesia

Philippines

Luxembourg

Greece

Netherlands

Norway

Hong Kong

Portugal

Spain

Germany

Taiwan

Turkey

Mexico

Canada

USA

Venezuela

Colombia

Ecuador

Peru

Chile

Guatemala

Puerto Rico

Jamaica

Israel

The world seen economically… RMS Ltd

Turkey1999

Iran2003

Pakistan2005

India2001

Indonesia2004

Taiwan1999

Cities with more than 500,000 inhabitants

Within 100 km of an active fault system

Not within 100 km of a major active fault system

Istanbul -100,000s Tehran -

millions

Himalayan front -millions

West Sumatra -500,000

Some examples of large potential seismic disasters

TEHRAN

Destroyed in:

population: 10-12 million

4th century BC

855 AD

958

1177

1830

J. Hollingsworth & M.J. Bolourchi

Tehran

fold

J. Hollingsworth & M.J. Bolourchi

Tehran

NorthTehranFault

Himalayan front -millions

Some examples of large potential seismic disasters

2005; 54,000 dead

Islamabad

The biggest natural disaster ever?

Earthquakes: dead1556 Shensi, China 830,000 1920 Haiyuan, China 235,0001923 Tokyo, Japan 143,0001976 Tangshan, China >243,000

Coastal cyclones and windstorms1737 Calcutta 300,0001876 Bangladesh 215,0001881 Haifeng, China 300,0001970 Bangladesh 300,000

Floods1642 China (dam burst) 900,0001887 China (Huang Ho) 900,0001931 China (Yangtze Kiang) 1,400,0001938 China (dam demolition) 500,0001959 N. China 2,000,000

Data from Munich Re

Differences between the geologic

and seismographic realms

The multi-disciplinary nature of earthquake science

Charles Darwin -- the father of neotectonics!

Two aspects of earthquake geology

Neotectonics

Paleoseismology

Neotectonic “domains” of Taiwan

(Shyu et al., 2005, JGR)

T. RockwellPaleoseismology

Summary of Offsets