Images

USGS Hawaiian Volcano Observatory scientists investigate a portion of the Great Crack in the Keaiwa flow field on Kīlauea Volcano's Southwest Rift Zone. USGS photo.

This rapidly moving ‘A‘ā lava flow was one of several that advanced down the west flank of Mauna Loa during the volcano's 1950 eruption. The massive flow, tens of meters (yards) high, traveled from the Southwest Rift Zone vent to the ocean, a distance of about 18 km (11 mi), in around 18 hours.

Video of spattering along the north margin of Kīlauea Volcano's summit lava lake.

A USGS Hawaiian Volcano Observatory chemist conducts thermal imaging measurements as part of a geochemical survey on Mauna Loa's upper Southwest Rift Zone in March 2016. Areas like the one shown here can indicate where gases are escaping from magma at depth. USGS photo.

This image of Kīlauea Volcano's summit, probably taken in the 1860s from a site near where Jaggar Museum in Hawai‘i Volcanoes National Park is located today, was once thought to be the first photograph of Kīlauea. It shows part of the caldera rim and floor with a fuming Halema‘uma‘u Crater near the center of the image. USGS/HVO photo archives.

This daguerreotype image, captured in 1855 by Hugo Stangenwald, is the earliest known photograph of Kīlauea Volcano. Although scratched and faded, the 161-year-old photo shows a line of steaming vents across the floor of Kīlauea's summit caldera as viewed from a location near today's Volcano House Hotel. The caldera rim is visible in the lower third of the image.

During the Mauna Loa 1950 eruption, three large, fast-moving lava flows advanced down the west flank of the volcano, each crossing the main highway before reaching the ocean. The Ka‘apuna flow, shown here, traveled from the Southwest Rift Zone vent (7,800 ft elevation) to the coast in just 17 hours, creating a huge steam plume as lava flowed into the sea.

This small-scale map shows Kīlauea's June2th lava flow boundaries on March 25, 2016, in relation to the eastern part of the Island of Hawai‘i. The area of the flow field on February 20 is shown in pink, while widening and advancement of the flow field as mapped on March 25 is shown in red. Pu‘u ‘Ō‘ō lava flows erupted prior to June 27, 2014, are shown in gray.

Kīlauea Volcano's summit eruption began on March 19, 2008, and continues today. The lava lake is contained within the Overlook crater, which is set within the larger Halema‘uma‘u Crater. In this February 28, 2016, photo, the lava lake surface was just 30 m (100 ft) below the rim of the Overlook crater. Spattering is visible in the southeast portion of the lake.

Footprints made in muddy ash during Kilauea's 1790 eruption are reminders that people experienced the largest explosive eruption in Hawai‘i in 1,000 years. More than 80, and possibly several hundred, people were killed by the eruption soon after the footprints were made.

One of the new tools deployed by the USGS Hawaiian Volcano Observatory to better monitor the current unrest on Mauna Loa is a webcam focused on the volcano's Southwest Rift Zone, which has been the site of eruptions in 1903, 1916, 1919, 1926, and 1950.

As the sun rose above Mauna Kea (background) on July 6, 1975, eruptive fissures along the Northeast Rift Zone of Mauna Loa fed voluminous ‘a‘ā lava flows that quickly moved down the north flank of the volcano.

Though the park celebrates its 100th anniversary on August 1, 2016, its main attractions-Kilauea and Mauna Loa volcanoes-have been adding to the land mass of Hawaii’s “Big Island” for at least 400,000 years.

Preview image for video: A rockfall on the east rim of the summit vent within Kīlauea Volcano's Halema‘uma‘u Crater triggered a small explosive event at 3:51 a.m., HST, on January 8, 2016. Explosive events like this occur more frequently when the lava lake level is relatively high, as it has been this past week—around 30-35 m (100-115 ft) below the vent rim.

In this photo of Kīlauea Volcano's summit lava lake, the light-colored rock in the vent wall to the left of the spattering lava shows were a rockfall occurred on January 2. The shadow of the gas plume appears as a brown streak perpendicular to the dark-colored lava on the floor of Halema‘uma‘u Crater.

On January 4, a rockfall within the Overlook vent at the summit of Kīlauea generated another small explosive event at 3:18 a.m., HST. In this image, captured by a USGS Hawaiian Volcano Observatory webcam, the dusty gas plume can be seen rising from the vent after rocks impacted the lava lake.

The November 25, 2015, breakout that began as a rupture from the tube supplying the June 27th lava flow advanced slowly to the northeast of Pu‘u ‘Ō‘ō (background) and reached the forest in mid-December, but still poses no immediate threat to Puna communities. USGS image.

This view shows the north rim of Kīlauea Caldera, with the Hawaiian Volcano Observatory and Hawai‘i Volcanoes National Park's Jaggar Museum perched at the rim for ideal views of summit activity. Mauna Kea is in the distance, partially obscured by clouds, and Mauna Loa's Northeast Rift Zone extends off the left edge of the photo.

On December 30, 2015, an HVO geologist wore protective gear during collection of a fresh lava sample for chemical analysis from a pāhoehoe breakout along scattered Pu‘u ‘Ō‘ō lava flows. Inset image caption: Metadata is written on a bag that holds a sample taken from pāhoehoe that was collected on August 18, 2006.

TOP: Mauna Loa weekly earthquake rates between 2010 and September 17, 2015. Blue bars indicate the number of earthquakes that were located by the USGS Hawaiian Volcano Observatory seismic network. Earthquakes of all magnitudes are plotted. Subtle increases in earthquake rates started in mid-2013, while more obvious changes in rates started in 2014.

After 25 years of slumber, Mauna Loa woke with a spectacular, but short-lived, eruption that began just before midnight on July 5. Lava fountains soon erupted from fissures extending across the length of Moku‘āweoweo, Mauna Loa's summit caldera, and into the upper ends of the volcano's northeast and southwest rift zones.