Earthquakes aren't usually a cause for festivities.

As the calendar marks 100 years since San Francisco suffered its most devastating natural disaster, however, the city is teeming with a peculiar energy. Blending the solemn and the celebratory, history and high tech, the centennial anniversary has become a uniquely San Franciscan event.

The earthquake that struck the city at 5:12 a.m. on April 18, 1906, is believed to have measured as high as 8.25 on the Richter scale.

Lasting more than 40 seconds, the temblor caused streets to ripple like waves and leveled vast tracts of the city's buildings. The massive fires that swept through the area after the earthquake incinerated much of what was left; over 3,000 people perished from the disasters.

Citywide Remembrances

Earlier this month, the

San Francisco Ballet pressed an STS-1 seismometer into service, transmitting the real-time movement of the nearby Hayward Fault to the company's opera house. There, the seismic waves were translated into an improvisational musical composition as one of the company's dancers responded to it in an eight-minute solo performance.

The bizarre ballet was one of the many commemorative events taking place during the month of April and coming to a head Tuesday, the anniversary of the great quake.

Museums throughout the Bay Area have organized exhibits dedicated to the quake. "After the Ruins, 1906 and 2006: Rephotographing the San Francisco Earthquake and Fire" at the

Legion of Honor museum provides a haunting sense of the scope of the destruction. The exhibit juxtaposes photographs of the apocalyptic, postearthquake ruins with modern images of the same streets.

To get an even more firsthand experience, visit

Presidio Park and explore the refugee tent camp, a re-creation of one of the many camps that sprang up to shelter the 250,000 people left homeless by the quake and fire.

On Market Street, one of the original wooden shacks that were mass-produced following the quake is on display. At the time the cabins reportedly cost $135 to construct and could be rented for $2 a month; today, a condo of only slightly larger proportions starts at $500,000.

The

Westin St. Francis Hotel will serve a special breakfast Tuesday for the earthquake's survivors and their families. The menu is identical to the breakfast the hotel served 100 years ago on the morning of the quake, including chilled rhubarb stew, griddle cakes with "flannel" pancake butter and maple syrup and fresh scrambled eggs with black truffles.

A hotel spokesperson said that the centennial was drawing more visitors than past anniversaries of the big quake. One survivor, she noted, was bringing 25 family members for the anniversary.

The city's official commemoration begins early in the morning at Lotta's Fountain on Market Street, a central meeting point that served as a bulletin board in the days following the quake. Survivors will lay a wreath at the fountain and observe a moment of silence. Various other ceremonies will take place throughout the day, including the painting of the "little giant" fire hydrant in the Mission District, which miraculously yielded water after the quake and is credited with saving parts of the Mission from conflagration.

While the San Francisco Earthquake remains one of the worst natural disasters in U.S. history, it also sparked the transition from the city's infamous Barbary Coast days of vice and licentiousness to its rebirth as the West Coast's premier metropolis.

Of course, the idiosyncratic character at the heart of San Francisco never really went away.

That spirit is alive and well at North Beach's Saloon, where a crapulous crew sat around sipping beers early one afternoon this April. Reputed to be San Francisco's oldest bar, the saloon dates back to 1861 and is one of the few buildings in North Beach to have made it through the quake.

A gravel-voiced bartender by the name of Rebel recounted the legend of how the Saloon survived the big one.

Apparently, she explained, the brothel once located on the top floor provided a safe haven from which firemen and patrons could hose down the burning embers that swarmed around the building's base.

"Those who weren't fraternizing were watering, and those who were fraternizing weren't watering," she explained matter-of-factly.

To commemorate the anniversary, Rebel said she was planning to dress in a period costume and hire a piano man to regale the crowd with honky-tonk music -- pending her boss's approval.

Don't look for any fancy, earthquake-inspired cocktails at the Saloon, though.

"Our drink specials are shots and beer," lectured a stern Rebel. "No frou-frou drinks."

Those seeking a swanker centennial could head down the block to

Enrico's on Broadway, where bartenders will concoct a special "earthquake" cocktail (the exact contents of which were still undetermined at press time) and guests will be treated to a glass of

prosecco for a special 10 p.m. toast.

And San Francisco's restaurants are not passing up on the chance to capitalize on the anniversary. Several eateries, including

One Market, Faz and

Scoma's, will offer special $19.06 prix fixe lunch menus throughout the week.

Come dinner time, however, the price of the commemorative menu at One Market escalates to a not-quite-as-symbolic $29.06.

Centennial or not, it seems, business is still business.