UserDisplay v2.4 video captures - Feb 2013

The M3.5 Aromas earthquake (April 13, 2012) occured just east of Santa Cruze not far from the epicenter of the 1989 Loma Prieta earthquake. ShakeAlert delivered an alert with an initial magnitude estimate of 3.2 climbing to 3.4 in 2 sec. The warning appeared in the UserDisplay (in Berkeley) with 25 sec of warning. Although this event did not generate any felt shaking in the Bay Area, it demonstrates the speed of the current ShakeAlert system. In a repeat of the Lama Prieta earthquake, ShakeAlert could provide ~20 sec of warning to San Francisco and Oakland.

• Aromas - mov file
  

Simulated UserDisplay warning in Berkeley for a repeat of the Loma Prieta earthquake. This window would pop-up on your computer desktop and count down until the shaking is felt at your location. The user location is shown by the house, set to San Francisco in this video. The estimated intensity of shaking (moderate in this case) and the countdown are specific to the user location.

• Loma Prieta - mov file
  

Capitol Hill Briefing - Earthquake early warning - September 28, 2012

This 10 minute presentation provided an overview of the current status of early warning in California. It was was part of a USGS organized briefing on Capitol Hill to staffers on both the House and Senate sides.

• USGS EEW briefing: Powerpoint file
  

Earthquake early warning overview presentation - April 2012

This 15 minute presentation gives an overview of what earthquake early warning is, how it is currently being used in Japan, the current status of development in the US, and finally possible applications of early warning. There are four videos included in the presentation.

• EEW summary presentation: Powerpoint file
  

25 sec warning for San Francisco and Oakland - UserDisplay recording

The M3.5 Aromas earthquake (April 13, 2012) occured just east of Santa Cruze not far from the epicenter of the 1989 Loma Prieta earthquake. ShakeAlert delivered an alert with an initial magnitude estimate of 3.2 climbing to 3.4 in 2 sec. The warning appeared in the UserDisplay (in Berkeley) with 25 sec of warning. Although this event did not generate any felt shaking in the Bay Area, it demonstrates the speed of the current ShakeAlert system. In a repeat of the Lama Prieta earthquake, ShakeAlert could provide ~20 sec of warning to San Francisco and Oakland.

• Screen capture of UserDisplay in Berkeley - mov file
  

Earthquake early warning - UserDisplay demo - Loma Prieta

Demonstration of how an earthquake alert can be received and displayed on a computer. This video shows the ShakeAlert UserDisplay for a scenario earthquake in northern California: a repeat of the Loma Prieta earthquake. This window would pop-up on your computer desktop and count down until the shaking is felt at your location. The user location is shown by the house, set to San Francisco in this video. The estimated intensity of shaking (moderate in this case) and the countdown are specific to the user location.

• UserDisplay demo - mov file
  

Earthquake early warning overview presentation - fall 2011

This 15 minute presentation gives an overview of what earthquake early warning is, how it is currently being used in Japan, the current status of development in the US, and finally possible applications of early warning. There are four videos included in the presentation. The video files have to be downloaded from the links that are provided on the slides with the videos.

• EEW summary presentation: Powerpoint file
  
• EEW summary presentation: pdf version
  
• EEW summary presentation handout: 6 slides per page
  

Seismograms

The Berkeley Earthquake
The "Berkeley Earthquake" occurred on the Hayward Fault at 1:24 am on June 26 1994 and was a magnitude 4.2 event. The figures show the three components (BHZ (bottom) is vertical; BHN (middle) is north-south horizontal; and BHE (top) is east-wast horizontal) recorded at station BKS which is in the Byerly Vault (photos below) on the UC Berkeley campus. The P-wave arrives first at about 187 sec and is relatively low amplitude but clearly distinguishable from the background noise seen before 187 sec. The S-wave starts with the big pulse arriving at about 189 sec and contains most of the energy. There is only 2 sec between the P and S because the station is so close to the earthquake.

Earthquake animation: M8.0 on the San Andreas Fault

This animation shows a magnitude 8.0 earthquake on the San Andreas Fault. This earthquake is about the same magnitude as the 1906 event and runs in realtime. As the rupture propagates from the north to the south, radiating P-wave energy is represented as red circles and S-wave energy as yellow. The total rupture takes 2 to 3 minutes to complete, and it is not until the rupture reaches the San Francisco Bay Area that most of the damage occurs in the Bay Area.

Earthquake early warning

Seismic stations in California and Japan
There are about 300 seismic stations in California today that be used at the basis of an earthquake early warning system. All of these stations would benefit from upgrades to their equipment allowing data to stream more rapidly to the network control centers providing a few additional seconds of warning. Japan, shown at the same scale, uses over 1000 instruments for its early warning system. California's warning system would benefit from an additional 300 stations to fill in the gaps in the current network.

Alum Rock AlertMap (left)
On October 30, 2007 the magnitude 5.4 Alum Rock earthquake rippled across the San Francisco Bay Area. The largest earthquake in the region since the 1989 Loma Prieta earthquake, it was felt by most people but caused little damage. The CISN early warning test system named ElarmS caught the earthquake. This map shows the distribution of ground intensity predicted using the first few seconds of data recorded by seismometers near the epicenter in San Jose. The epicenter is shown as a star and the estimated magnitude is 5.2. The warmer colors show stronger shaking near the epicenter and the cooler colors show weaker shaking at greater distances. The predicted ground shaking is very accurate. The data used to generate this map was available a few seconds before the shaking was felt in San Francisco.

Earthquakes, faults and seismic station maps

Seismic station/seismometers - Byerly vault

In Strawberry Canyon above the UC Berkeley campus and home to the Berkeley Digital Seismic Network Station BKS.

Seismic station/seismometers - PASSCAL deployments

Seismic stations deployed in various regions. These are "temporary" stations meaning that they are deployed for 2-4 years as part of regional seismic network.

Memorial Stadium

Built in 1923, the stadium straddles the Hayward Fault which runs goalpost to goalpost. Continuous creep on the fault has caused the building to deform over time.

Japan

Turkey