It is estimated that Hualālai rose above sea level about 300,000 years ago. Despite maintaining a very low level of activity since its last eruption in 1801, and having been unusually inactive for the past 2,000 years, Hualālai is still considered active and is expected to erupt again sometime in the next century. Lava flows represent by far the greatest danger in a possible future Hualalai eruption, because although explosive pyroclastic eruptions have occurred during the Holocene epoch (the last 10,000 years), they are relatively rare and cover only limited parts of the volcano. USGS Graphic This map shows the location of the Wahapele vent (star) and the lava flow (red) at Hualalai volcano.
It is approximately three-quarters of the area of the 1800-1801 eruption, and is the third largest known for Hualalai in terms of area covered. Future Hualalai eruptions may pose a direct threat to Kailua-Kona and surrounding communities. Although 200 years have passed since the last Hualalai eruption, it is almost certain that it will erupt again. The source of this eruption was the Wahapele Crater, a vent on the southern flank of Hualalai at 1,540 meters (5,053 feet) high.
Alkaline eruptions in Hualalai have generally been much less explosive than those at neighboring Kohala and Mauna Kea volcanoes. Hualalai erupts much less frequently than its neighbors, with centuries rather than years or decades separating eruptions. Compared to Kilauea and Mauna Loa, Hualalai poses a different challenge in monitoring changes in activity.
For residents of the Kona area, keep in mind that Hualalai hasn't erupted since 1801; Mauna Loa is considered active but hasn't erupted since 1984. During this period, no microearthquake swarms or harmonic tremors (both indicative of magma migration) have been recorded, although Hualalai experiences several magnitude 4 earthquakes each year. Hualalai, Mount Hualalai, Hualalai Mountain or Hualalai Volcano: it's just one name, Hualalai.