HOW DO ALL THESE BOUNDARIES WORK TOGETHER? PACIFIC NORTHWEST AND SOUTHWEST BRITISH COLUMBIA

HOW DO ALL THESEBOUNDARIES WORK TOGETHER?PACIFIC NORTHWEST ANDSOUTHWEST BRITISH COLUMBIA

HOW DO ALL THESEBOUNDARIES WORK TOGETHER?PACIFIC NORTHWEST ANDSOUTHWEST BRITISH COLUMBIA

North American Plate Movement

HOW DO ALL THESEBOUNDARIES WORK TOGETHER?PACIFIC NORTHWEST ANDSOUTHWEST BRITISH COLUMBIA

Pacific Plate MovementAnd Mendicino Fault (SanAndreas extension)

HOW DO ALL THESEBOUNDARIES WORK TOGETHER?PACIFIC NORTHWEST ANDSOUTHWEST BRITISH COLUMBIA

SMALL “MID-OCEAN”RIDGES DIVERGENT

GORDA RIDGE

HOW DO ALL THESEBOUNDARIES WORK TOGETHER?PACIFIC NORTHWEST ANDSOUTHWEST BRITISH COLUMBIA

SMALL “MID-OCEAN”RIDGES DIVERGENT

JUAN DE FUCA RIDGE

HOW DO ALL THESEBOUNDARIES WORK TOGETHER?PACIFIC NORTHWEST ANDSOUTHWEST BRITISH COLUMBIA

SMALL “MID-OCEAN”RIDGES DIVERGENT

EXPLORER RIDGE

HOW DO ALL THESEBOUNDARIES WORK TOGETHER?PACIFIC NORTHWEST ANDSOUTHWEST BRITISH COLUMBIA

SEAFLOOR SPREADING ANDTRANSFORM FAULT

HOW DO ALL THESEBOUNDARIES WORK TOGETHER?PACIFIC NORTHWEST ANDSOUTHWEST BRITISH COLUMBIA

SEAFLOOR SPREADING ANDTRANSFORM FAULT

HOW DO ALL THESEBOUNDARIES WORK TOGETHER?PACIFIC NORTHWEST ANDSOUTHWEST BRITISH COLUMBIA

SEAFLOOR SPREADING ANDTRANSFORM FAULT

HOW DO ALL THESEBOUNDARIES WORK TOGETHER?PACIFIC NORTHWEST ANDSOUTHWEST BRITISH COLUMBIA

North American Plate (black and white) CONVERGING (white dashes) with Juan de Fuca Plate (blue and yellow).

Can You See it on Google Earth?

1. Divergent boundaries

2. Convergent boundary

3. Transform faults4. Juan de Fuca

Plate and direction

5. Pacific Plate and direction

6. North American Plate and direction

7. Zones of Active Volcanicity

And a Hotspot!

Coas

tal U

plift

Puge

t-Will

amett

e Lo

wla

nds

Activ

e Vo

laca

nos

Currently Active

Oldest Lavas

NorthAmericaPlate

J.D.FPacificPlate

PacificPlate

PACIFIC NORTHWESTCASCADEMOUNTAI

N

CASCADE MOUNTAINS

PUGET- WILLAMETTE

LOWLANDS

OLYMPIC MOUNTAINS

COAST RANGE

NORTH AMERICAN PLATE

JUAN DE FUCA PLATE

PACIFICOCEAN

NORTH AMERICAN PLATE

JUAN DE FUCA PLATE

PLATES LOCKIN PLACE

BETWEEN EARTHQUAKES

NORTH AMERICAN PLATE

JUAN DE FUCA PLATE

CONVERGENCE CAUSESUPWARD BUCKLING OF

COASTAL AREAS

Energy stored as in a bent cane.

DURING ERTHQUAKES

NORTH AMERICAN PLATE

JUAN DE FUCA PLATE

PLATES UNLOCK

Energy in earthquakeand tsunami

Coastlinesubsides

BETWEEN EARTHQUAKES

NORTH AMERICAN PLATE

JUAN DE FUCA PLATE

Plates lock back togetherAfter release of energy by

earthquake

Coastline slowlyRe-emerges.

Source: Rhodes, Tuttle, Horton, Doner, Kelsey, Nelson and Cisternas, EOS, 87, May 2006.

Tsunami Deposits, SouthernChile. Dark bands are organicsoils, lighter greys are marinesands deposited by tsunamis.

TSUNAMI MARCH 2011

Displacement duringEarthquake March 2011.

Source: Simons et al., 2011 Science Express

PUEGET SOUND

3,500BPTidal Marsh

PUEGET SOUND

3,300BPEarthquake

PUEGET SOUND

3,200 BPEmergence

PUEGET SOUND

3,000 BPForestedUpland

PUEGET SOUND

3,000 BPEarthquakeSubmersion

PUEGET SOUND

2,700 BPEarthquakeSubmergence

PUEGET SOUND

400EmergenceForest

PUEGET SOUND

400EarthquakeSubmersion

PUEGET SOUND

700Emergence

PUEGET SOUND

700EarthquakeSubmersion

PUEGET SOUND

900Emergence

PUEGET SOUND

900Earthquake

PUEGET SOUND

1700EmergenceForestedUplands

PUEGET SOUND

1700EarthquakeSubmersion

Simulation of 1700 Earthquake and Tsunami

PUEGET SOUND

2000Emergence

PUEGET SOUND

AVERAGE LENGTH OF TIME BETWEEN EARTHQUAKES 300 yrs

PUEGET SOUND

AVERAGE LENGTH OF TIME BETWEEN EARTHQUAKES 300 yrs

1700 ?

SUBSTUTUTE DEPTH FOR TIMETIME

TIM

E

DEPT

H

1700

1700

900700 900700

3300BP 3000BP

3300BP

3000BP

Present

Geologists’ Principle of Superposition