EOTW #6 Earthquake Early Warning Systems

This event of the week is really more of a “monitoring and mitigation tool” of the week: the Earthquake Early Warning (EEW) system. This potentially life-saving tool has been in the news recently as the US government prepares the next budget. But, what is it exactly, how does it work, who would it help save, and where has it been used successfully? I think that it is important for us all to be aware of the science behind the EEW and to also be aware that there are countries that already have early warning systems and that they have already proven to be successful. So, for this week, I would like us all to learn more about the status of EEW in the US, how it would work, what type of seismic network is needed, and compare/contrast where we are in the stage of development versus other countries that already have this type of system operational.

  1. Read all the earthquake early warning system sections on the following webpage:  https://earthquake.usgs.gov/research/earlywarning/
  2. Briefly, how does the early warning system work?
  3. List the countries that currently have early warning systems in place (hint – the US does not yet have a fully operational version so should not be included in this list)
  4. See if you can find a recent example from the news where an early warning system alerted people ahead of an earthquake – how much time did they have to take cover? What type of alert was used (text, siren, combination?)

13 thoughts on “EOTW #6 Earthquake Early Warning Systems”

  1. Briefly, how does the early warning system work?
    In an earthquake, a rupturing fault sends out P-waves (arrive first) and S-waves (arrive next, but cause most damage). Sensors detect the P-wave and immediately transmit data to an earthquake alert center where the location and size of the quake is determined and updated as more data becomes available. A message from the alert center is then transmitted to phones and computers of each individual and calculates the expected intensity and arrival time of shaking and their location.

    List the countries that currently have early warning systems in place
    Mexico, Japan, Turkey, Romania, China, Italy, and Taiwan

    See if you can find a recent example from the news where an early warning system alerted people ahead of an earthquake – how much time did they have to take cover? What type of alert was used (text, siren, combination?)
    For the 2008 magnitude 7.9 quake in Wenchuan, which left more than 80,000 people dead, the system alerted some people in the region more than a minute before the initial tremor struck in Jiuzhaigou county. In the capital Chengdu, about 300km from the epicenter, people were notified of the quake 71 seconds before had via messages sent to their mobile phones. In Wenchuan, about 200km south of Jiuzhaigou, people were given 40 seconds warning before the quake. People 95km from the epicentre in Longnan, Gansu province, were warned 19 seconds before the quake.

  2. The P-wave or Primary wave is what first is detected by the Early Warning Systems (EWS). This wave travels quicker than the other waves of an earthquake and is much less destructive.

    Some of the countries that have good EWS are Japan, China, Taiwan. In fact, Japans EWS made a big difference in the earthquake that caused the famed failure of the Fukushima Daiichi Nuclear power plant. Japans EWS stopped bullet trains and began to shut down parts of the power plant long before the arrival of the fatal tsunami. Japans system is multifaceted using Wireless Emergency Alerts (WEA) via messages sent to cell phones, TV announcements, as well as radio. What failed was the tsunami detection system. Its original projections were nowhere near the actual heights of the tsunami.

  3. How does the earthquake early warning system work (EEW)? An earthquake produces two types of waves: P waves and S waves. P waves travel much faster, but most of the damage is caused by slower moving S waves (this is what really shakes buildings around). The EEW works by signaling an alert when the P waves are detected, which can give some warning as to how intense the S waves are going to be, and when they are going to happen. Can provide a warning of a few seconds to a few minutes, depending on how far away the earthquake happens from a sensing station.

    Some countries that have fully implemented systems are Japan, Tawain, and China. There are several other countries that have some version of a EEW, although not as extensive.

    I found an blog that an earthquake that occurred in Mexico (who has an EEW in some parts of the country), that said there was up to 90 seconds of warning on Sept 8, 2017 earthquake. Sirens were used to warn people.

    http://blogs.ucdavis.edu/egghead/2017/09/20/useful-earthquake-early-warning-systems/

  4. The Earthquake Early Warning system combines the science and technology gathers information from expected waves and sends out alerts to devices and people when an earthquake is detected. The system can alert emergency responders, businesses, medical personnel, power stations/ grid facilities and the general public from seconds to minutes which can helps save lives.

    Sensors are places 6- 12 miles apart from each other. When an earthquake happens. Sensors detect the P-waves before the damaging S- waves arrive and sends out alerts to devices. The alerts include information such as the intensity and when the quake is projected to arrive.

    The countries currently using EEW technology are: Mexico, Japan, Turkey, Romania, China, Italy, and Taiwan

    The recent article I found was in the South China Morning Post
    (PUBLISHED : Thursday, 10 August, 2017, 8:15pm)
    discussing how the system alerted people in the August 8th Sichuan earthquake http://www.scmp.com/news/china/society/article/2106309/chinas-early-earthquake-warning-system-gives-people-life-saving

    The system notified people 71 seconds before the quake hit.

    The alert used was “[There was a] sudden sound like an air defense alarm,” then a “woman’s sharp voice reading the countdown [to the quake]”, other alerts were send out to various platforms of social media.

  5. 1. Briefly, how does the early warning system work?
    Warning systems work by monitoring seismic stations. “It detects and measures Earth’s ground motion. These vibrations are similar to sound waves in air, but span a wide frequency range that extends well below the threshold for human hearing. The seismometer’s sensors are extremely sensitive and can pick up a broad spectrum of motions ranging from low-amplitude background vibrations, such as those generated by wind or pounding surf, to signals from local, regional, and distant earthquakes. The sensitivity of the station depends on how quiet the local conditions are–the lower the “background noise” from human and natural sources such as traffic and swaying trees, the more likely the station will be able to detect faint earthquake signals. Sites are chosen to minimize the background noise as much as is practical, while still allowing access for the installation of the equipment” (USArray, n.d). The earthquake early warning system works by monitoring the P waves which travel much faster than s waves. This warning can provide officials and experts with a few minutes or sometimes seconds to warn the public which can help save lives.

    2. List the countries that currently have early warning systems in place (hint – the US does not yet have a fully operational version so should not be included in this list)
    “Japan currently has the most sophisticated early warning systems in the world” (source). Other countries that have early warning systems are Mexico, china and Italy.

    3. See if you can find a recent example from the news where an early warning system alerted people ahead of an earthquake – how much time did they have to take cover? What type of alert was used (text, siren, combination?)
    An example of an early warning system being used was with the Mexico City’s early earthquake warning system in 2014. This gave more than a minute of warning before major shaking occurred from the 7.2 earthquake. One of the first methods to warn the public was through TV broadcasts.
    Earthquake Early Warning. (n.d.). Retrieved March, 2018, from
    https://earthquake.usgs.gov/research/earlywarning/news.php
    LIN II, BECERRA. (2014). Watch early earthquake warning system in action in Mexico City.
    Retrieved March, 2018, from http://www.latimes.com/local/lanow/la-me-ln-early-earthquake-warning-mexico-20140419-story.html
    USARRAY . (n.d.). How. Retrieved March 07, 2018, from
    http://www.usarray.org/public/about/how

  6. How does the earthquake early warning system work (EEW)?

    In an earthquake, a rupturing fault sends out P-waves (arrive first) and S-waves (arrive second) the Sensors that detect the P-wave immediately transmit the data to an earthquake alert system where the location and estimated potential size of the quake is determined and continuously updated as more data becomes available. A message from the alert center is transmitted to phones, computers, and systems giving the expected intensity, arrival time, and location of shaking.

    List the countries that currently have early warning systems in place
    Japan, Mexico, Turkey, China, Italy, and Taiwan

    See if you can find a recent example from the news where an early warning system alerted people ahead of an earthquake – how much time did they have to take cover? What type of alert was used (text, siren, combination?)

    while doing research for my case study i found this cutting edge news story from Japan in 2011:

    https://www.railway-technology.com/features/feature122751/

    more impressive then a cell phone getting an alert, this was a machine talking to another machine and shutting it down safely,
    A brief 12-15 seconds before the massive 8.9 earthquake in 2011 hit mainland Japan, a seismometer at Kinkazan belonging to the country’s eastern rail operator JR East sent an automatic stop signal to the Shinkansen – Japan’s high-speed bullet train – electric power transmission system, triggering the emergency brake on 33 trains, saving countless lives. this is the first time in history earthquake monitoring equipment has communicated with transportation machinery to stop its movement and save lives. the question is, why don’t we have this? it relay seems like a must for fast trains in seismically active regions.

  7. 1. When an earthquake occurs, a fault sends out powerful seismic waves that can be measured both in intensity and speed. When an EEW receives the motion of a P wave, it then analyzes the P waves to determine the size and speed of the following waves. If the EEW determines that the earthquake is likely to do serious damage, it sends out a warning to the nearest major city via either a message to your phone or computer that tells you the expected time, duration, and intensity of shaking.

    2. Mexico, Japan, Turkey, Romania, China, Italy and Taiwan all use an EEW.

    3. An earthquake in Wenchaun, China which left more than 80,000 people dead was actually recorded on the EEW. The EEW sent out notifications to peoples mobile phones up to 71 seconds before the shaking started. This is more than enough time for people to get away from a large building they are inside, or to get underneath a doorway or a table if they aren’t able to escape. The message was broadcasted to peoples mobile phones via text message. Additionally, the warning was broadcasted on public access terminals.

  8. 1. Briefly, how does the early warning system work?

    Early warning systems work by detecting the arrival of seismic waves produced by an earthquake. When an earthquake occurs compressional P-waves and transverse S-waves radiate outward from the ruptured fault. The faster P-waves travel through the landscape until they reach a seismic sensor, which detects the wave and immediately transfers data to a regional processing center. The information is then analyzed. The earthquakes location, type, and size are determined and broadcasted to alert individuals of the event and allow them adequate time to prepare for shaking.

    2. List the countries that currently have early warning systems in place (hint – the US does not yet have a fully operational version so should not be included in this list)

    Mexico, Japan, Turkey, Romania, China, Italy, and Taiwan currently have active early warning systems in place.

    3. See if you can find a recent example from the news where an early warning system alerted people ahead of an earthquake – how much time did they have to take cover? What type of alert was used (text, siren, combination?)

    On March 11, 2011 a M9.1 megathrust earthquake occurred 230 miles off the coast of Japan. Thanks to Japan’s early warning system, local residents likely had 80 seconds to prepare for shaking. The alert, which was broadcasted on television, the internet and through text messages.

    https://www.technologyreview.com/s/423274/80-seconds-of-warning-for-tokyo/

  9. The Earthquake Early Warning system detects the P-waves produced by an earthquake, which are the first to be produced. The P-waves can arrive seconds or minutes in advance of the S-waves that an earthquake produces, which are those that cause damage at the surface. When the EEW system detects these P-waves, it sends out a warning to surrounding communities so that they can take shelter or get to a safe location.
    Some countries that have very well-implemented EEW systems are Mexico, Japan, Turkey, Romania, China, Italy, and Taiwan, according to the USGS.
    A semi-recent use of an EEW system was in the 2011 Tohoku earthquake, when a TV, text, and internet message was sent out 80 seconds in advance of the earthquake’s effects arriving.

  10. How does early warning work?
    A series of sensors detects seismic activity. Information from sensors is transferred to regional networks where it is analyzed. Motion records from the sensor stations is reviewed real-time to triangulate the earthquake and determine a preliminary magnitude. If the earthquake meets a predetermined threshold alerts are broadcasted to the public.

    What countries have early warning systems?
    Mexico, Japan, Turkey, Romania, China, Italy, and Taiwan all have early warning systems, with Japan’s being the most sophisticated.

    Real-world example of early warning systems working:
    Mexico suffered from one of the largest earthquakes in their history on September 7th, 2017. However, before the massive quake struck some residents in Mexico had over one minute to prepare thanks to a broadcast from Mexico’s early warning system. Government radio channels issued alerts, and sirens blared for over twenty seconds before the shaking began.

    http://www.latimes.com/world/la-fg-mexico-earthquake-20170908-story.html

    http://www.latimes.com/world/la-me-mexico-quake-earth-warning-20170908-htmlstory.html

    https://twitter.com/ManceraMiguelMX/status/906070032266002433

    https://qz.com/1082191/an-earthquake-early-warning-system-helped-spare-mexico-city-trumps-budget-would-kill-it-in-the-us/

  11. EOTW Earth Quake Early Warning Systems

    In very basic terms, the way that early warning systems work is Simple. There are sensors that are positioned 6-12 miles from each other. These sensors communicate with a central monitoring station. The initial wave the sensors pick up is the faster, less destructive wave called a “P” wave. After the P wave, the slower and more destructive “S” wave follows. Once a sensor picks up the wave, the message is ultimately sent to an individuals computer or cell phone. This warning will tell a person how intense the quake is and how much time they have to seek shelter.

    Mexico, Japan, Turkey, Romania, China, Italy, and Taiwan are the only countries that currently have early warning systems in place. In Mexico, their system mainly lays off the coast. This can give as much as a one minute warning to Mexico City. Japan has been using their EWS since 2007. It is the most advanced in the world and has proven its self. Italy has a system in the southern part of the country. They have the ability to know the location, intensity and speed of the quake as well as sending EEWS alerts. Taiwan’s alert system has been proven as well. They regularly hold drills to keep the public ready. Romania has a redundant system. They have two EEWS’s that parallel and validate each other simultaneously. China has recently made some upgrades to theirs. They now service nearly half of the population of China.

    On August 8th, 2017, China had an earthquake hit in Jiuzhaigou , county. The system worked to alert fire departments, police and government agencies. Schools were alerted ranging from 5-38 seconds in advance. Some schools did not receive the alert due to the system being turned off. So far this system has warned the population of 38 destructive earth quakes.
    http://en.people.cn/n3/2017/0810/c90000-9253819.html

  12. Briefly, how does the early warning system work?

    A series of sensors triangulates an epicenter and determines a preliminary magnitude of an event. Based on the first wave (P-wave), the sensors determine if the event is above or below reporting magnitude. If it is above, it sends out an early warning message to cell phones and broadcasts in the regions, giving residents up to a minute warning ahead of the damaging S-waves.

    List the countries that currently have early warning systems in place (hint – the US does not yet have a fully operational version so should not be included in this list)

    The system is well implemented in both Japan and Mexico. Similar early warning systems are also found in Romania, Taiwan, and Turkey.

    See if you can find a recent example from the news where an early warning system alerted people ahead of an earthquake – how much time did they have to take cover? What type of alert was used (text, siren, combination?)

    http://temblor.net/earthquake-insights/mexico-city-buildings-sway-in-m7-2-earthquake-6391/

    Based on this article, It appears that residents in Mexico City get about a minute warning prior to feeling the shaking. The article talks about tourists checking into their AirBnB during the Feb 2018 7.2M event, and being confused by the warning sirens, to which their host explained what it warns of.

  13. Briefly, how does the early warning system work?

    An early warning system is used to prevent damage and loss of life. Various seismic sensors throughout a given area are placed to sense S and P waves sent out by an earthquake. Once sensed, protocols and alerts pre-setup is activated to warn the area of the coming threat. The warning may only come a few seconds before the quake but still is better than no warning at all.

    List the countries that currently have early warning systems in place (hint – the US does not yet have a fully operational version so should not be included in this list)

    Japan
    Mexico
    Romania
    Taiwan
    Turkey

    See if you can find a recent example from the news where an early warning system alerted people ahead of an earthquake – how much time did they have to take cover? What type of alert was used (text, siren, combination?)

    I found this article about how the early warning system in Napa in 2104 worked but they needed more fund to make it better:
    http://www.latimes.com/science/la-me-earthquakes-early-warning-20160204-story.html

    http://www.latimes.com/local/california/la-me-quake-early-warning-20141215-story.html

    They use seismic stations and historical data.

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