The Great 1906 San Francisco Earthquake Documentary

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  • Опубликовано: 21 июн 2023
  • This program first aired on PBS on October 4, 1988.
    The California earthquake of April 18, 1906 ranks as one of the most significant earthquakes of all time. Today, its importance comes more from the wealth of scientific knowledge derived from it than from its sheer size. Rupturing the northernmost 296 miles (477 kilometers) of the San Andreas fault from northwest of San Juan Bautista to the triple junction at Cape Mendocino, the earthquake confounded contemporary geologists with its large, horizontal displacements and great rupture length. Indeed, the significance of the fault and recognition of its large cumulative offset would not be fully appreciated until the advent of plate tectonics more than half a century later. Analysis of the 1906 displacements and strain in the surrounding crust led Reid (1910) to formulate his elastic-rebound theory of the earthquake source, which remains today the principal model of the earthquake cycle.
    At almost precisely 5:12 a.m., local time, a foreshock occurred with sufficient force to be felt widely throughout the San Francisco Bay area. The great earthquake broke loose some 20 to 25 seconds later, with an epicenter near San Francisco. Violent shocks punctuated the strong shaking which lasted some 45 to 60 seconds. The earthquake was felt from southern Oregon to south of Los Angeles and inland as far as central Nevada. The highest Modified Mercalli Intensities (MMI's) of VII to IX paralleled the length of the rupture, extending as far as 80 kilometers inland from the fault trace. One important characteristic of the shaking intensity noted in Lawson's (1908) report was the clear correlation of intensity with underlying geologic conditions. Areas situated in sediment-filled valleys sustained stronger shaking than nearby bedrock sites, and the strongest shaking occurred in areas where ground reclaimed from San Francisco Bay failed in the earthquake. Modern seismic-zonation practice accounts for the differences in seismic hazard posed by varying geologic conditions.
    As a basic reference about the earthquake and the damage it caused, geologic observations of the fault rupture and shaking effects, and other consequences of the earthquake, the Lawson (1908) report remains the authoritative work, as well as arguably the most important study of a single earthquake. In the public's mind, this earthquake is perhaps remembered most for the fire it spawned in San Francisco, giving it the somewhat misleading appellation of the "San Francisco earthquake". Shaking damage, however, was equally severe in many other places along the fault rupture. The frequently quoted value of 700 deaths caused by the earthquake and fire is now believed to underestimate the total loss of life by a factor of 3 or 4. Most of the fatalities occurred in San Francisco, and 189 were reported elsewhere.

Комментарии • 15

  • @user-ij1sx3yc5e
    @user-ij1sx3yc5e Месяц назад +1

    118 years ago today - The Great Quake and Fire of 1906. My family survived but lost their business. The dynamite lines took their home. Insurance paid out$.03 on the dollar. Starting over was hard for my immigrant family but they got to.

  • @user-bm5ef8nd7f
    @user-bm5ef8nd7f 11 месяцев назад +2

    Sa

  • @bradley8232
    @bradley8232 10 месяцев назад

    "promosm"

  • @mayarajput188
    @mayarajput188 11 месяцев назад +10

    Alhamdollillah proud to have Islam coz it shows Dat only Allah is mighty n nobody

    • @SymphonyBrahms
      @SymphonyBrahms 5 месяцев назад +1

      Jesus Christ is the King of the Universe.

    • @oldmansportsog2514
      @oldmansportsog2514 3 месяца назад +1

      Muslim faith came after Christianity and is basically a bootleg version that keeps women oppressed, in. Muslims nations women are there to pop out babies that’s it they have ZERO rights

    • @Quetzalcoatl_Feathered_Serpent
      @Quetzalcoatl_Feathered_Serpent 3 месяца назад +2

      Preaching how your religion is greater than others is one of the reasons why humanity keeps failing from achieving peace.
      Same as the one that preaches of his.
      Neither religions are better or greater

    • @TheDoctor1225
      @TheDoctor1225 2 месяца назад +1

      @@Quetzalcoatl_Feathered_Serpent Oh I don't know. One speaks of brotherhood and love between all of mankind and has things in it such as "Do unto others as you would have them do unto you," "Be ye kind, one to another, tenderhearted, forgiving one another..." The other speaks of open warfare to be waged against any and all who do not follow Allah and that any methods you can use to work against them are all right.
      "Better" may be a subjective term, but I know which one I'd put that label on. Besides, your dogmatic comments left off the most important part - "in my opinion."

    • @TheDoctor1225
      @TheDoctor1225 2 месяца назад

      That would be a more impressive statement, I'm sure, if you could put together a coherent sentence that didn't sound like a pre-school child with a mouthful of cookies.