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

BOUNDARIES WORK TOGETHER? HOW DO ALL THESE BOUNDARIES WORK TOGETHER? PACIFIC NORTHWEST AND SOUTHWEST BRITISH COLUMBIA North American Plate Movement

BOUNDARIES WORK TOGETHER? HOW DO ALL THESE BOUNDARIES WORK TOGETHER? PACIFIC NORTHWEST AND SOUTHWEST BRITISH COLUMBIA Pacific Plate Movement And Mendico Fault (San Andreas extension)

BOUNDARIES WORK TOGETHER? HOW DO ALL THESE BOUNDARIES WORK TOGETHER? PACIFIC NORTHWEST AND SOUTHWEST BRITISH COLUMBIA SMALL “MID-OCEAN” RIDGES DIVERGENT GORDA RIDGE

BOUNDARIES WORK TOGETHER? HOW DO ALL THESE BOUNDARIES WORK TOGETHER? PACIFIC NORTHWEST AND SOUTHWEST BRITISH COLUMBIA SMALL “MID-OCEAN” RIDGES DIVERGENT JUAN DE FUCA RIDGE

BOUNDARIES WORK TOGETHER? HOW DO ALL THESE BOUNDARIES WORK TOGETHER? PACIFIC NORTHWEST AND SOUTHWEST BRITISH COLUMBIA SMALL “MID-OCEAN” RIDGES DIVERGENT EXPLORER RIDGE

BOUNDARIES WORK TOGETHER? HOW DO ALL THESE BOUNDARIES WORK TOGETHER? PACIFIC NORTHWEST AND SOUTHWEST BRITISH COLUMBIA SEAFLOOR SPREADING AND TRANSFORM FAULT

BOUNDARIES WORK TOGETHER? HOW DO ALL THESE BOUNDARIES WORK TOGETHER? PACIFIC NORTHWEST AND SOUTHWEST BRITISH COLUMBIA SEAFLOOR SPREADING AND TRANSFORM FAULT

BOUNDARIES WORK TOGETHER? HOW DO ALL THESE BOUNDARIES WORK TOGETHER? PACIFIC NORTHWEST AND SOUTHWEST BRITISH COLUMBIA SEAFLOOR SPREADING AND TRANSFORM FAULT

BOUNDARIES WORK TOGETHER? HOW DO ALL THESE BOUNDARIES WORK TOGETHER? PACIFIC NORTHWEST AND SOUTHWEST BRITISH COLUMBIA North American Plate (black and white) CONVERGING (white dashes) with Juan de Fuca Plate (blue and yellow).

PACIFIC NORTHWEST JUAN DE FUCA NORTH AMERICAN PLATE MOUNTAINS CASCADE MOUNTAIN MOUNTAINS PUGET- WILLAMETTE LOWLANDS OLYMPIC MOUNTAINS COAST RANGE NORTH AMERICAN PLATE JUAN DE FUCA PACIFIC OCEAN

PLATES LOCK IN PLACE JUAN DE FUCA PLATE NORTH AMERICAN PLATE

BETWEEN EARTHQUAKES CONVERGENCE CAUSES UPWARD BUCKLING OF COASTAL AREAS Energy stored as in a bent cane. JUAN DE FUCA PLATE NORTH AMERICAN PLATE

DURING ERTHQUAKES PLATES Coastline UNLOCK subsides Energy in earthquake and tsunami JUAN DE FUCA PLATE NORTH AMERICAN PLATE

Plates lock back together After release of energy by BETWEEN EARTHQUAKES Plates lock back together After release of energy by earthquake Coastline slowly Re-emerges. JUAN DE FUCA PLATE NORTH AMERICAN PLATE

Tsunami Deposits, Southern Chile. Dark bands are organic soils, lighter greys are marine sands deposited by tsunamis. Source: Rhodes, Tuttle, Horton, Doner, Kelsey, Nelson and Cisternas, EOS, 87, May 2006.

TSUNAMI MARCH 2011

Displacement during Earthquake March 2011. Source: Simons et al., 2011 Science Express

PUEGET SOUND 3,500BP Tidal Marsh

PUEGET SOUND 3,300BP Earthquake

PUEGET SOUND 3,200 BP Emergence

PUEGET SOUND 3,000 BP Forested Upland

PUEGET SOUND 3,000 BP Earthquake Submersion

PUEGET SOUND 2,700 BP Earthquake Submergence

PUEGET SOUND 400 Emergence Forest

PUEGET SOUND 400 Earthquake Submersion

PUEGET SOUND 700 Emergence

PUEGET SOUND 700 Earthquake Submersion

PUEGET SOUND 900 Emergence

PUEGET SOUND 900 Earthquake

PUEGET SOUND 1700 Emergence Forested Uplands

PUEGET SOUND 1700 Earthquake Submersion

Simulation of 1700 Earthquake and Tsunami

PUEGET SOUND 2000 Emergence

PUEGET SOUND AVERAGE LENGTH OF TIME BETWEEN EARTHQUAKES 300 yrs

PUEGET SOUND AVERAGE LENGTH OF TIME BETWEEN EARTHQUAKES 300 yrs ? 1700

SUBSTUTUTE DEPTH FOR TIME 1700 900 700 3300BP 3000BP Present Geologists’ Principle of Superposition