The Big One

The Big One was the devastating Magnitude 9.2 megathrust earthquake¹ which began with the San Andreas slip-strike² fault and triggered the full-margin rupture of the Cascadia Subduction³ zone. In a great upheaval, 1000 miles of coastal land shifted with violent force, triggering a 200ft tsunami whose backsplash was almost as devastating as its landing.

The disaster kicked the feet out from under the Pacific Union, opening it up to invasion from Deseret. Its infrastructure, which was already groaning under the weight of mass climate immigration and flooding, came crashing down.

Among the cities destroyed by the Big One were the Solano Tech Sprawl, Sacramento, Sonoma, Seattle, Portland, and many, manby more.

In the wake of the Big One, the San Joaquin Valley's glacial melt lake was further deepend as the rise of the coastal land pushed the inland downwards, opening up subterranean water chasms which cause sinkholes even to this day

Most of the land along this fault have been rendered untenable. As if the geology wasn't bad enough, the release of pollutants from destroyed human civilization has made much of the land too toxic for farming or for safe groundwater

California fractured from one end of the horizon to the other, broken from heel to spine before the quake dove beneath the sea and emerged to flood unsuspecting Seattle. In its wake it ushered the sea into the valley and poisoned the water with the poison of industry and fumaroles.

Progression

Cascadia is no stranger to massive earthquakes and the tsunamis which echo after. The varied mythologies of its indigious tribes describe a flood which come without wave or warning, lifting canoes into the treetops and sweeping the unfortunate to their deaths. It was a battle between Whale and Thunderbird and it shook the earth, raised the sea, and filled the air with the rumble of vast wings.

Foreshadowed

By the 1980s, advancements in technology and technique allowed humanity to build a geological timeline, to calculate the cadence of tectonic quakes and project that forward into the future. They found the Whale and the Thunderbird: a subduction zone where the Juan De Fuca plate butts under the North American plate. Each time the energy of that friction is released, it explodes with enough force redefine the coastline.

The realization was chilling. In the time since that mythologized conflict between Whale and Thunderbird, the population of the Western Seaboard had grown to 30 million.

The faults of the west coast rumbled, but did not yet break

Time Paases

By 224X, that population had quintupled from natural growth and climate exodus from the south and east, halved from birthrate and ecological collapse and the resultant horsemen of pestilence and famine, and steadily ticked up again towards 90 million -- most of whom lived along the coast defined by the border of the two plates. After generations of declining education and waning resources, the warnings of the 1980s were barely remembered and of scant concern compared to the struggle of everyday survival.

A friction builds within Earth's tectonics as they shift a millimeter at a time, resulting in tectonic earthquakes of various classifications. The Big One was a quake so large

The earth roared with the effort, and the ocean echoed back, spilling over its boundaries is a heave that bowed the horizon and

Timeline

Animal Panic

One hour before the Earthquake, animals with a sensity to high-frequency seismic noise -- such as cats, dogs, and mice -- exhibited anxious and panicked behaviors.

Shake Alert

The Bureau of Geosurveillance detects seismic noise in its oceanic sensors. Sirens blare across the Cascadia Enclave as an alert is played, giving people precious seconds to abandon the building they're in.

The Cataclysm

Gas leaks and explosions

Dams break

Outcomes

Orphan Wave Tsunamis

Mt. Ranier explodes

Deseret Attacks with Ireheart

Inland Sea Forms

Legacy