(BIVN) – There is an updated visual resource on earthquakes in Hawaiʻi, available online.
The USGS Hawaiian Volcano Observatory has updated the slide show, Earthquakes in Hawaii: What you need to know, described as “an overview of damaging earthquakes in the Hawaiian Islands and what you can do to protect yourself when the next one strikes.”
The release is in anticipation of the Great Hawaii ShakeOut, which happens on October 17, 2019, joining millions of people worldwide who on the same day will practice how to “Drop, Cover, and Hold On” as a way to be prepared for the next big quake.
As the slide show presentation explains, Hawaiʻi experiences thousands of earthquakes every year.
“Most of these earthquakes are closely related to volcanic processes in Hawaii, and are so small they can be detected only by seismometers,” but that “some earthquakes are large enough to cause damage and impact residents across the State of Hawaii.”
Since 1868, there have been more than 30 earthquakes with a magnitude 6.0 or greater. The presentation notes the difference between “magnitude” and “intensity”.
The USGS highlights some of the more powerful events, starting with the April 2, 1868 event in Kaʻū, the largest earthquake in Hawaiʻi’s recorded history.
The presentation also includes the most recent big earthquake: the magnitude-6.9 event that struck on May 4, 2018 as the eruption on the lower East Rift Zone of Kīlauea got underway.
The bottom line, the presentation concludes, is that Hawaiʻi “has a long history of destructive earthquakes” that “are equivalent in size to the strong earthquakes that occur along California’s San Andreas fault.” There is a 50% probability of a destructive magnitude-6.5 or higher earthquake striking the Hawaiian islands in the next 10 years, 75% in the next 20 years, and 97% in the next 50 years.