Kilauea briefly erupted Sunday night, the Hawaiian Volcano Observatory announced Monday.
According to an HVO report, a pair of fissures formed west of Napau Crater on Kilauea’s middle East Rift Zone likely between 9 p.m. and 10 p.m. From each fissure, lava flowed for about 50 meters before the eruption ceased.
The eruption does not appear to have impacted the nearby Hawaii Volcanoes National Park Napau campsite, but it may have partly covered a historic Pulu Station nearby, where pulu ferns were collected and processed.
While the eruption is over, sulfur dioxide continues to vent from the fissures, which may pose a hazard to people downwind of the site.
The eruption followed a period of increased seismic activity over the weekend.
Beginning Saturday evening, HVO observed “intense and localized earthquakes” between Maunaulu and Makaopuhi Crater within Hawaii Volcanoes National Park.
The quakes were accompanied by ground deformation patterns indicative of the expansion of underground cracks, and while the quakes have since diminished in intensity, that ground deformation continues.
On Sunday evening, HVO instruments detected a signal that typically indicates the venting of gas or steam, while seismometers in the middle East Rift Zone began recording a sustained low-frequency tremor.
All these indications pointed to the intrusion of magma into Kilauea’s middle East Rift Zone, and HVO raised its volcano alert level from Advisory to Watch. The aviation color code also was elevated from Yellow to Orange.
Those alert levels remain the same, while Chain of Craters Road — which HVNP shut to all users on Monday — is still closed.
In 2007, magma intrusion in the same general area led to a small eruption that covered an area roughly half the size of a football field. HVO reported Monday morning that a similarly small eruption could take place, and that depending on weather conditions, it might go undetected — which, evidently, it did.
Previous eruptions in the area between the 1960s and 1970s ranged from less than one day long to about two weeks long. However, the most recent eruption in the area lasted for more than 35 years near the Pu‘u‘o‘o vent.
HVO and HVNP will continue to monitor the situation and will provide updates as warranted.