Magnitude 4.9 Earthquake Strikes 119 km SSW of Merizo Village, Guam

A magnitude 4.9 earthquake struck 119 km SSW of Merizo Village, Guam, registering immediately across global broadband seismograph stations and triggering automated hypocentral calculations by international geophysical monitoring agencies.

The United States Geological Survey (USGS) Seismic Alert Network officially registered a magnitude 4.9 tectonic event centered at 119 km SSW of Merizo Village, Guam. Seismological sensors recorded the rupture at a hypocenter depth of 10 km Tsunami Flag: No tsunami warning indicated Status: REVIEWED The USGS monitors global seismic activity 24/7 to provide rapid automated alerts and reviewed scientific data for disaster response and public awareness.. Seismologists classify this hypocenter depth as a shallow crustal event. Shallow earthquakes typically concentrate high-frequency vibrational energy near the surface, amplifying ground acceleration and potential structural stress within proximal population centers. - Moment Magnitude: M4.9 recorded via calibrated broadband seismograph telemetry. - Epicentral Region: 119 km SSW of Merizo Village, Guam. - Hypocenter Depth: 10 km Tsunami Flag: No tsunami warning indicated Status: REVIEWED The USGS monitors global seismic activity 24/7 to provide rapid automated alerts and reviewed scientific data for disaster response and public awareness. beneath the Earth's crust. - Tsunami Hazard Evaluation: No tsunami warning indicated Status: REVIEWED The USGS monitors global seismic activity 24/7 to provide rapid automated alerts and reviewed scientific data for disaster response and public awareness.. - Monitoring Agency: USGS National Earthquake Information Center (NEIC) in coordination with international geophysical observatories. The tectonic regime underlying 119 km SSW of Merizo Village, Guam is governed by high-velocity crustal stress accumulation along major lithospheric boundaries. In this sector, converging tectonic plates generate continuous compressive friction, where subducting oceanic slabs force their way beneath continental crust at rates ranging from 50 to 80 millimeters annually. Over extended decades, locked fault asperities store immense shear strain energy until sudden brittle failure occurs along active fault planes. The resulting slip releases accumulated elastic strain as seismic shockwaves that radiate outward in the form of compressive primary (P) waves and shearing secondary (S) waves. Based on initial instrumental calculations, estimated peak ground acceleration (PGA) in the immediate epicentral zone corresponded to an instrumental intensity capable of producing perceptible vibrations indoors and mild swaying of light fixtures. The Modified Mercalli Intensity (MMI) shake map parameters suggest light-to-moderate shaking depending on localized geological substrate: - Alluvial and Soft Sediments: Coastal and valley zones composed of unconsolidated sediment experience amplified ground motion, increasing susceptibility to resonance and soil liquefaction. - Bedrock Substrates: Hard rock formations attenuate wave amplitudes more rapidly, providing superior structural damping for engineered foundations. - Civil Defense Infrastructure: Municipal disaster response authorities recommend structural inspections of critical lifelines, including highway overpasses, water reservoirs, and electrical transmission grids. Following an earthquake of magnitude 4.9, subsequent aftershock sequences are expected within the rupture zone as the crust re-equilibrates. Seismologists emphasize that aftershocks can persist for several days to weeks, with decreasing frequency over time: - Drop, Cover, and Hold On: Civil defense agencies urge residents in affected areas to drop to their hands and knees, take cover under a sturdy desk or table, and protect their heads and necks until shaking ceases entirely. - Utility Checks: Inhabitants should visually inspect gas lines, municipal water connections, and electrical wiring for potential breaches prior to re-entering damaged buildings. - Emergency Preparedness: Maintain accessible emergency kits containing non-perishable food, potable water, battery-powered radios, and first aid supplies. This seismic dossier is synthesized directly from verified instrument readings provided by the USGS Seismic Alert Network and international geophysical observatories. The Chronicle Global climate and seismology desk maintains continuous automated and editorial oversight of active earthquake telemetry., situated around coordinates Calibrated seismic coordinates**.

Seismologists classify this hypocenter depth as a shallow crustal event. Shallow earthquakes typically concentrate high-frequency vibrational energy near the surface, amplifying ground acceleration and potential structural stress within proximal population centers.

• Moment Magnitude: M4.9 recorded via calibrated broadband seismograph telemetry.
• Epicentral Region: 119 km SSW of Merizo Village, Guam.
• Hypocenter Depth: 10 km Tsunami Flag: No tsunami warning indicated Status: REVIEWED The USGS monitors global seismic activity 24/7 to provide rapid automated alerts and reviewed scientific data for disaster response and public awareness.. Seismologists classify this hypocenter depth as a shallow crustal event. Shallow earthquakes typically concentrate high-frequency vibrational energy near the surface, amplifying ground acceleration and potential structural stress within proximal population centers. - Moment Magnitude: M4.9 recorded via calibrated broadband seismograph telemetry. - Epicentral Region: 119 km SSW of Merizo Village, Guam. - Hypocenter Depth: 10 km Tsunami Flag: No tsunami warning indicated Status: REVIEWED The USGS monitors global seismic activity 24/7 to provide rapid automated alerts and reviewed scientific data for disaster response and public awareness. beneath the Earth's crust. - Tsunami Hazard Evaluation: No tsunami warning indicated Status: REVIEWED The USGS monitors global seismic activity 24/7 to provide rapid automated alerts and reviewed scientific data for disaster response and public awareness.. - Monitoring Agency: USGS National Earthquake Information Center (NEIC) in coordination with international geophysical observatories. The tectonic regime underlying 119 km SSW of Merizo Village, Guam is governed by high-velocity crustal stress accumulation along major lithospheric boundaries. In this sector, converging tectonic plates generate continuous compressive friction, where subducting oceanic slabs force their way beneath continental crust at rates ranging from 50 to 80 millimeters annually. Over extended decades, locked fault asperities store immense shear strain energy until sudden brittle failure occurs along active fault planes. The resulting slip releases accumulated elastic strain as seismic shockwaves that radiate outward in the form of compressive primary (P) waves and shearing secondary (S) waves. Based on initial instrumental calculations, estimated peak ground acceleration (PGA) in the immediate epicentral zone corresponded to an instrumental intensity capable of producing perceptible vibrations indoors and mild swaying of light fixtures. The Modified Mercalli Intensity (MMI) shake map parameters suggest light-to-moderate shaking depending on localized geological substrate: - Alluvial and Soft Sediments: Coastal and valley zones composed of unconsolidated sediment experience amplified ground motion, increasing susceptibility to resonance and soil liquefaction. - Bedrock Substrates: Hard rock formations attenuate wave amplitudes more rapidly, providing superior structural damping for engineered foundations. - Civil Defense Infrastructure: Municipal disaster response authorities recommend structural inspections of critical lifelines, including highway overpasses, water reservoirs, and electrical transmission grids. Following an earthquake of magnitude 4.9, subsequent aftershock sequences are expected within the rupture zone as the crust re-equilibrates. Seismologists emphasize that aftershocks can persist for several days to weeks, with decreasing frequency over time: - Drop, Cover, and Hold On: Civil defense agencies urge residents in affected areas to drop to their hands and knees, take cover under a sturdy desk or table, and protect their heads and necks until shaking ceases entirely. - Utility Checks: Inhabitants should visually inspect gas lines, municipal water connections, and electrical wiring for potential breaches prior to re-entering damaged buildings. - Emergency Preparedness: Maintain accessible emergency kits containing non-perishable food, potable water, battery-powered radios, and first aid supplies. This seismic dossier is synthesized directly from verified instrument readings provided by the USGS Seismic Alert Network** and international geophysical observatories. The Chronicle Global climate and seismology desk maintains continuous automated and editorial oversight of active earthquake telemetry. beneath the Earth's crust.
• Tsunami Hazard Evaluation: No tsunami warning indicated Status: REVIEWED The USGS monitors global seismic activity 24/7 to provide rapid automated alerts and reviewed scientific data for disaster response and public awareness., situated around coordinates Latitude 12.328, Longitude 144.1189 Hypocenter Depth: 10 km Tsunami Flag: No tsunami warning indicated Status: REVIEWED The USGS monitors global seismic activity 24/7 to provide rapid automated alerts and reviewed scientific data for disaster response and public awareness.. Seismologists classify this hypocenter depth as a shallow crustal event. Shallow earthquakes typically concentrate high-frequency vibrational energy near the surface, amplifying ground acceleration and potential structural stress within proximal population centers. - Moment Magnitude: M4.9 recorded via calibrated broadband seismograph telemetry. - Epicentral Region: 119 km SSW of Merizo Village, Guam. - Hypocenter Depth: 10 km Tsunami Flag: No tsunami warning indicated Status: REVIEWED The USGS monitors global seismic activity 24/7 to provide rapid automated alerts and reviewed scientific data for disaster response and public awareness. beneath the Earth's crust. - Tsunami Hazard Evaluation: No tsunami warning indicated Status: REVIEWED The USGS monitors global seismic activity 24/7 to provide rapid automated alerts and reviewed scientific data for disaster response and public awareness.. - Monitoring Agency: USGS National Earthquake Information Center (NEIC) in coordination with international geophysical observatories. The tectonic regime underlying 119 km SSW of Merizo Village, Guam is governed by high-velocity crustal stress accumulation along major lithospheric boundaries. In this sector, converging tectonic plates generate continuous compressive friction, where subducting oceanic slabs force their way beneath continental crust at rates ranging from 50 to 80 millimeters annually. Over extended decades, locked fault asperities store immense shear strain energy until sudden brittle failure occurs along active fault planes. The resulting slip releases accumulated elastic strain as seismic shockwaves that radiate outward in the form of compressive primary (P) waves and shearing secondary (S) waves. Based on initial instrumental calculations, estimated peak ground acceleration (PGA) in the immediate epicentral zone corresponded to an instrumental intensity capable of producing perceptible vibrations indoors and mild swaying of light fixtures. The Modified Mercalli Intensity (MMI) shake map parameters suggest light-to-moderate shaking depending on localized geological substrate: - Alluvial and Soft Sediments: Coastal and valley zones composed of unconsolidated sediment experience amplified ground motion, increasing susceptibility to resonance and soil liquefaction. - Bedrock Substrates: Hard rock formations attenuate wave amplitudes more rapidly, providing superior structural damping for engineered foundations. - Civil Defense Infrastructure: Municipal disaster response authorities recommend structural inspections of critical lifelines, including highway overpasses, water reservoirs, and electrical transmission grids. Following an earthquake of magnitude 4.9, subsequent aftershock sequences are expected within the rupture zone as the crust re-equilibrates. Seismologists emphasize that aftershocks can persist for several days to weeks, with decreasing frequency over time: - Drop, Cover, and Hold On: Civil defense agencies urge residents in affected areas to drop to their hands and knees, take cover under a sturdy desk or table, and protect their heads and necks until shaking ceases entirely. - Utility Checks: Inhabitants should visually inspect gas lines, municipal water connections, and electrical wiring for potential breaches prior to re-entering damaged buildings. - Emergency Preparedness: Maintain accessible emergency kits containing non-perishable food, potable water, battery-powered radios, and first aid supplies. This seismic dossier is synthesized directly from verified instrument readings provided by the USGS Seismic Alert Network** and international geophysical observatories. The Chronicle Global climate and seismology desk maintains continuous automated and editorial oversight of active earthquake telemetry..
• Monitoring Agency: USGS National Earthquake Information Center (NEIC) in coordination with international geophysical observatories.

The tectonic regime underlying 119 km SSW of Merizo Village, Guam is governed by high-velocity crustal stress accumulation along major lithospheric boundaries. In this sector, converging tectonic plates generate continuous compressive friction, where subducting oceanic slabs force their way beneath continental crust at rates ranging from 50 to 80 millimeters annually.

Over extended decades, locked fault asperities store immense shear strain energy until sudden brittle failure occurs along active fault planes. The resulting slip releases accumulated elastic strain as seismic shockwaves that radiate outward in the form of compressive primary (P) waves and shearing secondary (S) waves.

Based on initial instrumental calculations, estimated peak ground acceleration (PGA) in the immediate epicentral zone corresponded to an instrumental intensity capable of producing perceptible vibrations indoors and mild swaying of light fixtures. The Modified Mercalli Intensity (MMI) shake map parameters suggest light-to-moderate shaking depending on localized geological substrate:

• Alluvial and Soft Sediments: Coastal and valley zones composed of unconsolidated sediment experience amplified ground motion, increasing susceptibility to resonance and soil liquefaction.
• Bedrock Substrates: Hard rock formations attenuate wave amplitudes more rapidly, providing superior structural damping for engineered foundations.
• Civil Defense Infrastructure: Municipal disaster response authorities recommend structural inspections of critical lifelines, including highway overpasses, water reservoirs, and electrical transmission grids.

Following an earthquake of magnitude 4.9, subsequent aftershock sequences are expected within the rupture zone as the crust re-equilibrates. Seismologists emphasize that aftershocks can persist for several days to weeks, with decreasing frequency over time:

• Drop, Cover, and Hold On: Civil defense agencies urge residents in affected areas to drop to their hands and knees, take cover under a sturdy desk or table, and protect their heads and necks until shaking ceases entirely.
• Utility Checks: Inhabitants should visually inspect gas lines, municipal water connections, and electrical wiring for potential breaches prior to re-entering damaged buildings.
• Emergency Preparedness: Maintain accessible emergency kits containing non-perishable food, potable water, battery-powered radios, and first aid supplies.

This seismic dossier is synthesized directly from verified instrument readings provided by the [USGS](/data) Seismic Alert Network and international geophysical observatories. The Chronicle Global climate and seismology desk maintains continuous automated and editorial oversight of active earthquake telemetry.