Hawaii Earthquake Felt Widely but Was Not Volcanic

A magnitude-4.5 earthquake struck off the west coast of Hawaiʻi Island on July 9, producing light shaking reported across the state but no expected damage or tsunami threat.

The U.S. Geological Survey said the quake was not driven by magma beneath Kīlauea or Mauna Loa. It came from deep bending within the Pacific plate under the weight of the Hawaiian Islands.

The quake struck deep beneath the ocean

The earthquake occurred at 8:17 p.m. HST, about 34 miles west-southwest of Captain Cook.

USGS placed the source roughly 24 miles below sea level, deep enough to distinguish it from most of the daily earthquakes generated within Hawaii’s active volcanic systems.

The agency received 275 public felt reports during the first hour.

Community responses indicated a maximum intensity of IV on the Modified Mercalli scale, corresponding to light shaking. Instrument readings were slightly lower at intensity III.

Reports extended across Hawaiʻi Island and as far as Oʻahu.

USGS said damage to buildings and infrastructure was not expected from the recorded shaking. Aftershocks remain possible for days or weeks, although no damaging sequence had been identified in the initial statement.

📰 Read Also: 2.9 Magnitude Quake Reported Near Chicago Area

The earthquake did not come from volcanic unrest

Hawaii’s location leads many people to connect every earthquake with an eruption.

That connection does not apply to this event.

The Hawaiian Volcano Observatory said the quake’s depth and offshore location identify it as a lithospheric-flexure earthquake. The islands’ enormous volcanoes press down on the oceanic crust and upper mantle, forcing the rigid plate to sag.

The rock can bend only so far before accumulated strain is released along a fault.

USGS compared the process to placing a bowling ball on a bed. The ball pushes the blankets downward while folds form around the weight.

The earthquake occurred inside that stressed, bending plate rather than within a shallow magma system.

The agency found no apparent impact on Kīlauea or Mauna Loa and said no effect on Kīlauea’s ongoing summit eruption was expected.

Deep events can be felt across a wider area

A moderate earthquake does not need to be shallow to attract reports from several islands.

USGS scientists said seismic waves from deep flexure events can travel efficiently through the dense lithosphere. That allows shaking energy to spread across a broader footprint before fading.

The result can feel confusing to residents.

A person far from the epicenter may notice movement even when the quake produces little or no structural damage near its source. The felt area can appear large compared with the event’s magnitude.

The depth also reduces the sharp surface shaking often associated with a shallow earthquake directly beneath a community.

That combination explains why the July 9 event was widely noticed without producing an emergency-damage report.

📰 Read Also: Fresh Health Warning Issued as New UK Heatwave Builds

Recent Hawaii earthquakes did not share one cause

Hawaiʻi Island has experienced several widely felt earthquakes during 2026.

A magnitude-6.0 event occurred beneath the west side of the island on May 22. A magnitude-4.6 event followed northwest of Keauhou on June 2, and a magnitude-4.7 quake struck east of Pepeʻekeo on June 9.

The Hawaiian Volcano Observatory’s analysis identified those three as flexure events caused by the load of the island chain.

Another magnitude-4.6 quake south of the island on June 16 came from a different process.

USGS associated that event with the deep Pāhala seismic swarm, which is thought to relate to magma-transport pathways beneath the southeast side of the island.

Depth alone therefore does not identify the cause.

Scientists compare location, faulting pattern, surrounding seismicity and volcanic monitoring data before deciding whether a quake reflects plate bending, magma movement or another fault system.

No tsunami was generated

The offshore location prompted immediate questions about a tsunami.

No tsunami threat was issued for Hawaiʻi after the July 9 earthquake.

Tsunamis generally require substantial displacement of the seafloor, commonly from a larger and shallower earthquake. A deep magnitude-4.5 flexure event does not normally move enough ocean floor to generate a destructive wave.

Residents should still rely on the NOAA Tsunami Warning Center after any strongly felt coastal earthquake rather than making assumptions from magnitude alone.

Official alerts can change when event parameters are refined.

What residents should watch next

The main near-term issue is ordinary aftershock monitoring.

USGS will continue checking for changes in earthquake activity, ground deformation and volcanic gas at Kīlauea and Mauna Loa. A deep flexure event does not prevent unrelated volcanic activity from continuing on its own timetable.

Residents who feel another earthquake should drop, cover and hold on, then check for official information after the shaking stops.

Public felt reports also help scientists compare instrument readings with the experience of people across the islands.

📰 Read Also: Flood Warnings Expand Across Chicago Suburbs Through Sunday

Sources

• USGS Hawaiian Volcano Observatory — July 9 earthquake statement

• USGS — Deep Hawaii earthquakes explained

• USGS — Event page

• NOAA — U.S. Tsunami Warning System

Read More

• NESO Power Warning Shows Heatwave Strain on Grid

• Three Children Dead as Sudden Storm Capsizes Boat on Geneva Lake

• Mexico vs England Delayed an Hour as Storm Hits Azteca