Hawaii Volcano: Why Kilauea Is Causing So Many Earthquakes

As if flooding an entire island with red-hot lava wasn’t enough, Hawaii’s Kilauea volcano has now triggered another earthquake. The Weather Channel reports that two explosions on Monday at the volcano’s summit sent ash into the air and triggered at least one magnitude 5.4 earthquake. Lava from Kilauea has already covered over 5,000 acres of the Big Island, and scientists say there’s no way to know when the volcano will stop erupting.

How Volcanoes Cause Earthquakes

An explosion at the summit on Saturday also triggered an earthquake of magnitude 5.2, but fortunately there was no recorded damage from the tremor. The Richter Scale categorizes tremors between magnitude 5 and 6 as moderate earthquakes that occur every 10 to 30 years. Not all earthquakes are related to volcanoes, but in the case of Kilauea, the movement of magma puts pressure on the tectonic plates below. The pressure causes the rocks around it to crack, and magma seeps into the cracks, building even more pressure. Every time the rock cracks, it makes a small earthquake.

Most quakes caused by magma pressure are too small to be registered on anything but sensitive instruments, but the tremor on Saturday could be felt as far away as Hilo, a 45-minute drive from Kilauea. The earthquakes caused by the volcano have been ongoing since its eruption on May 3, with the largest recorded on May 4 at magnitude 6.9 — nearly “severe” on the Richter Scale.

Evacuations Still Necessary

Roughly 600 homes have already been destroyed by Kilauea’s lava, which has covered at least 8 square miles in the Puna district. It continues to affect those living in the lower half of the district, with mandatory evacuations still in effect. The ash plumes sent up by the volcano have reached as high as 10,000 feet above sea level, making it easier for it to blow toward nearby communities. Residents of the Big Island have been warned to expect increased ash presence in the air, which could affect visibility. Were it just the earthquake affecting the area, the need to evacuate would be lessened considerably, but the lava spread is still active and extremely dangerous for residents.

More Earthquakes to Come

Unfortunately for the communities and natural resources around Kilauea, the more lava that continues to flow likely means more earthquakes. As long as the pressure from magma under the summit exists, there will be continued explosions and tremors, and scientists don’t know when it will show signs of stopping. On the flip side, there has been no reason yet to believe that the earthquakes may cause a third natural disaster — a tsunami — which is good, because that’s the last thing the island needs.