San Andreas is dramatic, but it gets one message right: prepared people stay safer.
Have a plan, download the MyShake Earthquake Early Warning app, and sign up for local tsunamis warnings where you live.

More Pop Culture Fridays coming soon from @berkeleyseismo 🌍📽️

\What the Movie Gets Right (Science)

A few fundamentals are accurate:
• The San Andreas marks the plate boundary
• Big earthquakes can last minutes
• Triggered earthquakes are real
• Water receding before a wave is a valid tsunami clue

What the Movie Gets Right (Safety)

The film nails some key safety behaviors:
• Drop, Cover, and Hold On
• Running during shaking = injuries
• Cell networks jamming after major quakes
• First aid and emergency planning matter

These scenes reflect real guidance!

The San Francisco Tsunami

A Golden Gate-sized tsunami makes for great cinema, but not real science. Because the San Andreas sits on land, it can’t generate large tsunamis. Small landslide-driven waves are possible, but not a 100-foot wall of water.

The Giant Cracking Ground Scene

The movie shows a massive canyon swallowing highways. Strike-slip faults don’t create giant gaps like this; they slide sideways, offsetting roads and fences, not opening voids. That dramatic “earth opening” effect only happens on faults with vertical motion.

The M9.6 Mega-Quake

The film opens with a magnitude 9.6 earthquake ripping across California. In reality, the San Andreas Fault cannot produce a quake that large, it isn’t long or deep enough. The largest likely event is around M8.3, still huge but far from a 9.6!🫨

During World War I, Wood worked at the National Bureau of Standards, designing a new kind of seismograph.

Harry O. Wood bridged early 20th-century geology and modern seismological instrumentation. His teaching at Berkeley, his contributions to the MMI scale, and his work on the Wood-Anderson seismograph defined how we measure and understand earthquake impacts today.

In the 1920’s, alongside J. A. Anderson, Harry O. Wood also developed the Wood-Anderson seismograph. Its precise records allowed scientists to quantify earthquake size, laying the groundwork for Charles Richter’s magnitude scale (1935).

With Frank Neumann, Wood devised the Modified Mercalli Intensity (MMI) Scale in 1931. This is still used worldwide to describe how strongly an earthquake is felt!

His seismograph used quartz crystals that converted ground vibrations into electrical signals. It was one of the earliest devices sensitive enough to locate artillery fire.

After the 1906 San Francisco earthquake, Wood joined Andrew Lawson’s investigation team. This experience shaped his lifelong focus on earthquake instrumentation and intensity studies.

Stay tuned for more earthquake history every #TBT @berkeleyseismo

Andrew Lawson built the foundations of modern earthquake science at UC Berkeley. The Berkeley Seismology Lab still carries forward his mission: observing, understanding, and preparing for earthquakes 🌍

Fun fact: He was a consulting geologist for the construction of the Golden Gate Bridge in the 1930s 🌉

Named after Lawson:
Lawson Adit: Earthquake research tunnel in the Berkeley Hills (built 1930s)
Lawson Peak (13,165 ft, Sequoia National Park)
Lawson Hill (1,128 ft, Contra Costa County)
Lawsonite: A mineral he first described in 1895, named in his honor

Lawson led the State Earthquake Investigation Commission after the 1906 San Francisco earthquake, producing the 1908 “Lawson Report”, documenting fault rupture, ground shaking, and damage.

Fun Fact: Andrew Lawson taught the first field class at UC Berkeley in 1891. Unusual for its time, this class included 3 women. 📚