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What is UTC, and why do you report earthquakes in UTC?

UTC stands for Coordinated Universal Time, and for this purpose is the same as GMT (Greenwich Mean Time).

Since the USGS and other seismic network agencies record earthquakes around the globe in all the various time zones, using a single standard time reference is best for record-keeping and exchange of data. The individual event pages with details about each earthquake use UTC for the reference time. Sometimes this means the UTC date of the earthquake is "the next day" from the date where you are.

The default time reference on the Latest Earthquakes list is your local time based on the time clock on your computer or mobile device. You can change this setting in the Settings panel ("gear" icon in upper right). Keep in mind that your local time might be different from the local time of the earthquake, even if you felt it. An earthquake offshore in the ocean or in a neighboring state might be in different time zone from yours.

NASA has a helpful website on Time Zones and Universal Time.

Related Content

link
Latest Earthquakes Interface

Where can I find current earthquake lists and maps for the world or for a specific area?

The Earthquake Hazards Program Latest Earthquakes Map displays earthquakes in near-realtime and up to the past 30 days of earthquakes. The interface includes three panels: a list of earthquakes, a map, and a settings/options panel. You can pan and zoom the map to view specific areas. Click on an event on the list or map for additional information and a link to the event page with all the details...

link

Where can I find current earthquake lists and maps for the world or for a specific area?

The Earthquake Hazards Program Latest Earthquakes Map displays earthquakes in near-realtime and up to the past 30 days of earthquakes. The interface includes three panels: a list of earthquakes, a map, and a settings/options panel. You can pan and zoom the map to view specific areas. Click on an event on the list or map for additional information and a link to the event page with all the details...

Learn More
link
“Did You Feel It?” community intensity map indicating the severity of shaking felt by people in central California during the So

Did I feel an earthquake? Can I report feeling an earthquake?

Report an earthquake experience or related observation through the Did You Feel It? citizen science webpage.The best way to do this is to click on the earthquake that you think you felt on one of the lists on the Earthquakes webpage, and then select the "Tell Us!" link.If you don't see the earthquake you think you felt, use the green "Report an Unknown Event" button on our Did You Feel It? page...

link

Did I feel an earthquake? Can I report feeling an earthquake?

Report an earthquake experience or related observation through the Did You Feel It? citizen science webpage.The best way to do this is to click on the earthquake that you think you felt on one of the lists on the Earthquakes webpage, and then select the "Tell Us!" link.If you don't see the earthquake you think you felt, use the green "Report an Unknown Event" button on our Did You Feel It? page...

Learn More
link
Latest Earthquakes Interface

Why is the earthquake that was reported/recorded by network X, or that I felt, not on the Latest Earthquakes map/list?

The USGS Latest Earthquakes map and lists show events that have been located by the USGS and contributing agencies within the last 30 days. They should NOT be considered complete lists of all events in the U.S. and adjacent areas and especially should NOT be considered complete lists of all magnitude 4.5 and greater events that occur around the globe.In most cases, we locate and report an...

link

Why is the earthquake that was reported/recorded by network X, or that I felt, not on the Latest Earthquakes map/list?

The USGS Latest Earthquakes map and lists show events that have been located by the USGS and contributing agencies within the last 30 days. They should NOT be considered complete lists of all events in the U.S. and adjacent areas and especially should NOT be considered complete lists of all magnitude 4.5 and greater events that occur around the globe.In most cases, we locate and report an...

Learn More
link
Earthquake Catalog Map Results Example

Why do some earthquakes disappear from the map/list?

The USGS and networks contributing to the Advance National Seismic System (ANSS) take great effort to provide accurate and timely earthquake information. Occasionally our systems produce erroneous information that is released to the public via our web pages or Earthquake Notification System. These mistakes are generally promptly identified by seismologists, removed from our web pages, and “delete”...

link

Why do some earthquakes disappear from the map/list?

The USGS and networks contributing to the Advance National Seismic System (ANSS) take great effort to provide accurate and timely earthquake information. Occasionally our systems produce erroneous information that is released to the public via our web pages or Earthquake Notification System. These mistakes are generally promptly identified by seismologists, removed from our web pages, and “delete”...

Learn More
link
Image: Closeup of the San Andreas Fault

Why isn't the fault on which the earthquake occurred or the distance to the nearest fault provided?

Seismologists evaluate the hypocenter location and the focal mechanism of an earthquake to decide if the earthquake occurs on a named fault. Research shows that many earthquakes occur on small, un-named faults located near well-known faults. For example, most of the aftershocks of the 1989 M6.9 Loma Prieta earthquake occurred on small, subsidiary faults within a few hundred meters of the mainshock...

link

Why isn't the fault on which the earthquake occurred or the distance to the nearest fault provided?

Seismologists evaluate the hypocenter location and the focal mechanism of an earthquake to decide if the earthquake occurs on a named fault. Research shows that many earthquakes occur on small, un-named faults located near well-known faults. For example, most of the aftershocks of the 1989 M6.9 Loma Prieta earthquake occurred on small, subsidiary faults within a few hundred meters of the mainshock...

Learn More
link
Screenshot of earthquake notification webpage

Can I get on a list to receive an email message when there is an earthquake? How do I sign up for earthquake notifications?  Are there any Feeds I can subscribe to?

Yes, please go to the USGS Earthquake Notification Services (ENS) to sign up for free emails or text messages to your phone. Use the default settings or customize ENS to fit your needs. Also check out the many different Earthquake Feeds.

link

Can I get on a list to receive an email message when there is an earthquake? How do I sign up for earthquake notifications?  Are there any Feeds I can subscribe to?

Yes, please go to the USGS Earthquake Notification Services (ENS) to sign up for free emails or text messages to your phone. Use the default settings or customize ENS to fit your needs. Also check out the many different Earthquake Feeds.

Learn More
link
Image: Installing Antenna and Solar Panel for Seismic Station

Why/When does the USGS update the magnitude of an earthquake?

The USGS often updates an earthquake's magnitude in the hours and sometimes days following the event. Updates occur as more data become available for analysis and more time-intensive analysis is performed. Additional updates are possible as part of the standard procedure of assembling a final earthquake catalog.There are physical and operational constraints on how quickly seismic data are...

link

Why/When does the USGS update the magnitude of an earthquake?

The USGS often updates an earthquake's magnitude in the hours and sometimes days following the event. Updates occur as more data become available for analysis and more time-intensive analysis is performed. Additional updates are possible as part of the standard procedure of assembling a final earthquake catalog.There are physical and operational constraints on how quickly seismic data are...

Learn More
link
Crop of OK earthquake

Why do so many earthquakes occur at a depth of 10km?

Ten kilometers is a "fixed depth". Sometimes data are too poor to compute a reliable depth for an earthquake. In such cases, the depth is assigned to be 10 km. Why that number? In many areas around the world, reliable depths tend to average 10 km or close to it. For example, if we made a histogram of the reliable depths in such an area, we'd expect to see a peak around 10 km. So if we don't know...

link

Why do so many earthquakes occur at a depth of 10km?

Ten kilometers is a "fixed depth". Sometimes data are too poor to compute a reliable depth for an earthquake. In such cases, the depth is assigned to be 10 km. Why that number? In many areas around the world, reliable depths tend to average 10 km or close to it. For example, if we made a histogram of the reliable depths in such an area, we'd expect to see a peak around 10 km. So if we don't know...

Learn More
link
Image for real-time earthquake data

How quickly is earthquake information posted to the USGS website and sent out via the Earthquake Notification Service (ENS) and other feeds?

USGS earthquake information mechanisms are all triggered by the same system, so they all receive the information at the same time. The time it takes for the system to receive the information primarily depends on the size and location of the earthquake:An earthquake in California is processed and posted to the system in 2.5 minutes (on average). This is because our seismic network is very extensive...

link

How quickly is earthquake information posted to the USGS website and sent out via the Earthquake Notification Service (ENS) and other feeds?

USGS earthquake information mechanisms are all triggered by the same system, so they all receive the information at the same time. The time it takes for the system to receive the information primarily depends on the size and location of the earthquake:An earthquake in California is processed and posted to the system in 2.5 minutes (on average). This is because our seismic network is very extensive...

Learn More
link
Image: Seismographs at the U.S. Geological Survey

Where can I see current or past seismograms?

The USGS Earthquake Hazards Program has helicorders (seismogram displays) available for several areas in the United States and the World.Our research partner IRIS (Incorporated Research Institutions for Seismology) has two applications, the Station Monitor and the Global Seismogram Viewer, for viewing seismograms. IRIS also supplies software that allows users to collect and view seismic data from...

link

Where can I see current or past seismograms?

The USGS Earthquake Hazards Program has helicorders (seismogram displays) available for several areas in the United States and the World.Our research partner IRIS (Incorporated Research Institutions for Seismology) has two applications, the Station Monitor and the Global Seismogram Viewer, for viewing seismograms. IRIS also supplies software that allows users to collect and view seismic data from...

Learn More
link
Magnitude 6.9 Earthquake off Japan on November 21, 2016

Why do USGS earthquake magnitudes differ from those published by other agencies?

Magnitude estimates for a given earthquake can vary between reporting agencies due to differences in methodology, data availability, and inherent uncertainties in seismic data. Individual agencies use magnitude estimation procedures designed to meet the agency's specific needs and monitoring capabilities. Even for well-recorded events, differences in magnitude of 0.2 or 0.3 units are common and...

link

Why do USGS earthquake magnitudes differ from those published by other agencies?

Magnitude estimates for a given earthquake can vary between reporting agencies due to differences in methodology, data availability, and inherent uncertainties in seismic data. Individual agencies use magnitude estimation procedures designed to meet the agency's specific needs and monitoring capabilities. Even for well-recorded events, differences in magnitude of 0.2 or 0.3 units are common and...

Learn More
Earthquake Catalog Map Results Example
link
Magnitude 7.9 Earthquake off Papua New Guinea
link
Latest Earthquakes
link
world map showing time zones
link
Wrecked buildings and washed-up boat far from water after the 2011 earthquake and tsunami in Japan in 2011.
link

The Global Seismographic Network

By
Natural Hazards, Earthquake Hazards, Geologic Hazards Science Center

Earthquake hazards: a national threat

Earthquakes are one of the most costly natural hazards faced by the Nation, posing a significant risk to 75 million Americans in 39 States. The risks that earthquakes pose to society, including death, injury, and economic loss, can be greatly reduced by (1) better planning, construction, and mitigation practices before earthquakes happen, and (2) providing critical and timely information to improv

ANSS-Advanced National Seismic System

USGS National Seismic Hazard Maps

The U.S. Geological Survey (USGS) recently completed new probabilistic seismic hazard maps for the United States, including Alaska and Hawaii. These hazard maps form the basis of the probabilistic component of the design maps used in the 1997 edition of the NEHRP Recommended Provisions for Seismic Regulations for New Buildings and Other Structures, prepared by the Building Seismic Safety Council a

NEIC - the National Earthquake Information Center

The National Earthquake Information Center of the US Geological Survey has three main missions. First, the NEIC determines as rapidly and as accurately as possible, the location and size of all destructive earthquakes that occur worldwide. Second, the NEIC collects and provides to scientists and to the public an extensive seismic database that serves as a solid foundation for scientific research.
link

Updated USGS Earthquake Monitoring Strategy Released

The USGS Earthquake Hazards Program recently released a new strategic plan for earthquake monitoring entitled the “Advanced National Seismic System –...

Read Article

Related Content

  • FAQ
    link
    Latest Earthquakes Interface

    Where can I find current earthquake lists and maps for the world or for a specific area?

    The Earthquake Hazards Program Latest Earthquakes Map displays earthquakes in near-realtime and up to the past 30 days of earthquakes. The interface includes three panels: a list of earthquakes, a map, and a settings/options panel. You can pan and zoom the map to view specific areas. Click on an event on the list or map for additional information and a link to the event page with all the details...

    link

    Where can I find current earthquake lists and maps for the world or for a specific area?

    The Earthquake Hazards Program Latest Earthquakes Map displays earthquakes in near-realtime and up to the past 30 days of earthquakes. The interface includes three panels: a list of earthquakes, a map, and a settings/options panel. You can pan and zoom the map to view specific areas. Click on an event on the list or map for additional information and a link to the event page with all the details...

    Learn More
    link
    “Did You Feel It?” community intensity map indicating the severity of shaking felt by people in central California during the So

    Did I feel an earthquake? Can I report feeling an earthquake?

    Report an earthquake experience or related observation through the Did You Feel It? citizen science webpage.The best way to do this is to click on the earthquake that you think you felt on one of the lists on the Earthquakes webpage, and then select the "Tell Us!" link.If you don't see the earthquake you think you felt, use the green "Report an Unknown Event" button on our Did You Feel It? page...

    link

    Did I feel an earthquake? Can I report feeling an earthquake?

    Report an earthquake experience or related observation through the Did You Feel It? citizen science webpage.The best way to do this is to click on the earthquake that you think you felt on one of the lists on the Earthquakes webpage, and then select the "Tell Us!" link.If you don't see the earthquake you think you felt, use the green "Report an Unknown Event" button on our Did You Feel It? page...

    Learn More
    link
    Latest Earthquakes Interface

    Why is the earthquake that was reported/recorded by network X, or that I felt, not on the Latest Earthquakes map/list?

    The USGS Latest Earthquakes map and lists show events that have been located by the USGS and contributing agencies within the last 30 days. They should NOT be considered complete lists of all events in the U.S. and adjacent areas and especially should NOT be considered complete lists of all magnitude 4.5 and greater events that occur around the globe.In most cases, we locate and report an...

    link

    Why is the earthquake that was reported/recorded by network X, or that I felt, not on the Latest Earthquakes map/list?

    The USGS Latest Earthquakes map and lists show events that have been located by the USGS and contributing agencies within the last 30 days. They should NOT be considered complete lists of all events in the U.S. and adjacent areas and especially should NOT be considered complete lists of all magnitude 4.5 and greater events that occur around the globe.In most cases, we locate and report an...

    Learn More
    link
    Earthquake Catalog Map Results Example

    Why do some earthquakes disappear from the map/list?

    The USGS and networks contributing to the Advance National Seismic System (ANSS) take great effort to provide accurate and timely earthquake information. Occasionally our systems produce erroneous information that is released to the public via our web pages or Earthquake Notification System. These mistakes are generally promptly identified by seismologists, removed from our web pages, and “delete”...

    link

    Why do some earthquakes disappear from the map/list?

    The USGS and networks contributing to the Advance National Seismic System (ANSS) take great effort to provide accurate and timely earthquake information. Occasionally our systems produce erroneous information that is released to the public via our web pages or Earthquake Notification System. These mistakes are generally promptly identified by seismologists, removed from our web pages, and “delete”...

    Learn More
    link
    Image: Closeup of the San Andreas Fault

    Why isn't the fault on which the earthquake occurred or the distance to the nearest fault provided?

    Seismologists evaluate the hypocenter location and the focal mechanism of an earthquake to decide if the earthquake occurs on a named fault. Research shows that many earthquakes occur on small, un-named faults located near well-known faults. For example, most of the aftershocks of the 1989 M6.9 Loma Prieta earthquake occurred on small, subsidiary faults within a few hundred meters of the mainshock...

    link

    Why isn't the fault on which the earthquake occurred or the distance to the nearest fault provided?

    Seismologists evaluate the hypocenter location and the focal mechanism of an earthquake to decide if the earthquake occurs on a named fault. Research shows that many earthquakes occur on small, un-named faults located near well-known faults. For example, most of the aftershocks of the 1989 M6.9 Loma Prieta earthquake occurred on small, subsidiary faults within a few hundred meters of the mainshock...

    Learn More
    link
    Screenshot of earthquake notification webpage

    Can I get on a list to receive an email message when there is an earthquake? How do I sign up for earthquake notifications?  Are there any Feeds I can subscribe to?

    Yes, please go to the USGS Earthquake Notification Services (ENS) to sign up for free emails or text messages to your phone. Use the default settings or customize ENS to fit your needs. Also check out the many different Earthquake Feeds.

    link

    Can I get on a list to receive an email message when there is an earthquake? How do I sign up for earthquake notifications?  Are there any Feeds I can subscribe to?

    Yes, please go to the USGS Earthquake Notification Services (ENS) to sign up for free emails or text messages to your phone. Use the default settings or customize ENS to fit your needs. Also check out the many different Earthquake Feeds.

    Learn More
    link
    Image: Installing Antenna and Solar Panel for Seismic Station

    Why/When does the USGS update the magnitude of an earthquake?

    The USGS often updates an earthquake's magnitude in the hours and sometimes days following the event. Updates occur as more data become available for analysis and more time-intensive analysis is performed. Additional updates are possible as part of the standard procedure of assembling a final earthquake catalog.There are physical and operational constraints on how quickly seismic data are...

    link

    Why/When does the USGS update the magnitude of an earthquake?

    The USGS often updates an earthquake's magnitude in the hours and sometimes days following the event. Updates occur as more data become available for analysis and more time-intensive analysis is performed. Additional updates are possible as part of the standard procedure of assembling a final earthquake catalog.There are physical and operational constraints on how quickly seismic data are...

    Learn More
    link
    Crop of OK earthquake

    Why do so many earthquakes occur at a depth of 10km?

    Ten kilometers is a "fixed depth". Sometimes data are too poor to compute a reliable depth for an earthquake. In such cases, the depth is assigned to be 10 km. Why that number? In many areas around the world, reliable depths tend to average 10 km or close to it. For example, if we made a histogram of the reliable depths in such an area, we'd expect to see a peak around 10 km. So if we don't know...

    link

    Why do so many earthquakes occur at a depth of 10km?

    Ten kilometers is a "fixed depth". Sometimes data are too poor to compute a reliable depth for an earthquake. In such cases, the depth is assigned to be 10 km. Why that number? In many areas around the world, reliable depths tend to average 10 km or close to it. For example, if we made a histogram of the reliable depths in such an area, we'd expect to see a peak around 10 km. So if we don't know...

    Learn More
    link
    Image for real-time earthquake data

    How quickly is earthquake information posted to the USGS website and sent out via the Earthquake Notification Service (ENS) and other feeds?

    USGS earthquake information mechanisms are all triggered by the same system, so they all receive the information at the same time. The time it takes for the system to receive the information primarily depends on the size and location of the earthquake:An earthquake in California is processed and posted to the system in 2.5 minutes (on average). This is because our seismic network is very extensive...

    link

    How quickly is earthquake information posted to the USGS website and sent out via the Earthquake Notification Service (ENS) and other feeds?

    USGS earthquake information mechanisms are all triggered by the same system, so they all receive the information at the same time. The time it takes for the system to receive the information primarily depends on the size and location of the earthquake:An earthquake in California is processed and posted to the system in 2.5 minutes (on average). This is because our seismic network is very extensive...

    Learn More
    link
    Image: Seismographs at the U.S. Geological Survey

    Where can I see current or past seismograms?

    The USGS Earthquake Hazards Program has helicorders (seismogram displays) available for several areas in the United States and the World.Our research partner IRIS (Incorporated Research Institutions for Seismology) has two applications, the Station Monitor and the Global Seismogram Viewer, for viewing seismograms. IRIS also supplies software that allows users to collect and view seismic data from...

    link

    Where can I see current or past seismograms?

    The USGS Earthquake Hazards Program has helicorders (seismogram displays) available for several areas in the United States and the World.Our research partner IRIS (Incorporated Research Institutions for Seismology) has two applications, the Station Monitor and the Global Seismogram Viewer, for viewing seismograms. IRIS also supplies software that allows users to collect and view seismic data from...

    Learn More
    link
    Magnitude 6.9 Earthquake off Japan on November 21, 2016

    Why do USGS earthquake magnitudes differ from those published by other agencies?

    Magnitude estimates for a given earthquake can vary between reporting agencies due to differences in methodology, data availability, and inherent uncertainties in seismic data. Individual agencies use magnitude estimation procedures designed to meet the agency's specific needs and monitoring capabilities. Even for well-recorded events, differences in magnitude of 0.2 or 0.3 units are common and...

    link

    Why do USGS earthquake magnitudes differ from those published by other agencies?

    Magnitude estimates for a given earthquake can vary between reporting agencies due to differences in methodology, data availability, and inherent uncertainties in seismic data. Individual agencies use magnitude estimation procedures designed to meet the agency's specific needs and monitoring capabilities. Even for well-recorded events, differences in magnitude of 0.2 or 0.3 units are common and...

    Learn More
  • Multimedia
    Earthquake Catalog Map Results Example
    link
    Magnitude 7.9 Earthquake off Papua New Guinea
    link
    Latest Earthquakes
    link
    world map showing time zones
    link
    Wrecked buildings and washed-up boat far from water after the 2011 earthquake and tsunami in Japan in 2011.
    link
  • Publications

    The Global Seismographic Network

    By
    Natural Hazards, Earthquake Hazards, Geologic Hazards Science Center

    Earthquake hazards: a national threat

    Earthquakes are one of the most costly natural hazards faced by the Nation, posing a significant risk to 75 million Americans in 39 States. The risks that earthquakes pose to society, including death, injury, and economic loss, can be greatly reduced by (1) better planning, construction, and mitigation practices before earthquakes happen, and (2) providing critical and timely information to improv

    ANSS-Advanced National Seismic System

    USGS National Seismic Hazard Maps

    The U.S. Geological Survey (USGS) recently completed new probabilistic seismic hazard maps for the United States, including Alaska and Hawaii. These hazard maps form the basis of the probabilistic component of the design maps used in the 1997 edition of the NEHRP Recommended Provisions for Seismic Regulations for New Buildings and Other Structures, prepared by the Building Seismic Safety Council a

    NEIC - the National Earthquake Information Center

    The National Earthquake Information Center of the US Geological Survey has three main missions. First, the NEIC determines as rapidly and as accurately as possible, the location and size of all destructive earthquakes that occur worldwide. Second, the NEIC collects and provides to scientists and to the public an extensive seismic database that serves as a solid foundation for scientific research.
  • News
    link

    Updated USGS Earthquake Monitoring Strategy Released

    The USGS Earthquake Hazards Program recently released a new strategic plan for earthquake monitoring entitled the “Advanced National Seismic System –...

    Read Article