Multimedia

Filter Total Items: 138
Mauna Loa Southwest Rift Zone's eruptions stopped traffic—and more...
June 9, 2016

Mauna Loa Southwest Rift Zone's eruptions stopped traffic—and more

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. Two earlier flows from this eruption reached the ocean in as little as three

...
Scientists search for the right "keys" to Mauna Loa...
May 19, 2016

Scientists search for the right "keys" to Mauna Loa

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.

Mauna Loa 1950 eruption: A lot of lava with little warning...
April 7, 2016

Mauna Loa 1950 eruption: A lot of lava with little warning

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. The glowing edges

...
Mauna Loa: Earth's largest active volcano is still stirring...
February 25, 2016

Mauna Loa: Earth's largest active volcano is still stirring

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. Webcam images of Mauna Loa's summit, Northeast Rift, and Southwest Rift (like the one shown here from the morning of

...
eruptive fissures along the Northeast Rift Zone of Mauna Loa
January 12, 2016

eruptive fissures along the Northeast Rift Zone of Mauna Loa

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.

Satellite image showing images of islands for Kilauea and Mauna Loa Hawaii
January 9, 2016

Kilauea, Mauna Loa Volcanoes Shape the Face of Hawaii

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. That expansion continues today as bright molten lava from Kilauea flows downslope across the coastal plain on its south flank, spilling over a cliff on its way to a

...
Mauna Loa 1975 Eruption...
September 17, 2015

Mauna Loa 1975 Eruption

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. After only 6 hours, the caldera and southwest rift

...
Mauna Loa - Earthquake and Deformation Data 2010-2015...
September 17, 2015

Mauna Loa - Earthquake and Deformation Data 2010-2016

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.
BOTTOM: Change in

...
Mauna Loa 1950 Eruption...
September 17, 2015

Mauna Loa 1950 Eruption

On June 1, 1950, a 2.4-km (1.5 mi) long fissure erupted high on Mauna Loa's Southwest Rift Zone at 9:04 p.m. Minutes later, the roar of lava fountains could be heard up to 24 km (15 mi) away. Within three hours, an ‘A‘ā lava flow crossed the main highway on the west coast of the Island of Hawai‘i and inundated the village of Pahoehoe (all villagers reached safety unharmed

...
USGS Volcano Alert Level for Mauna Loa Elevated from Normal to Advi...
September 17, 2015

Volcano Alert Level for Mauna Loa Elevated from Normal to Advisory

USGS Hawaiian Volcano Observatory scientists are closely monitoring recent signs of unrest on Mauna Loa, the largest active volcano on Earth. In this 1985 aerial photo, Mauna Loa looms above Kīlauea Volcano's summit caldera (left center) and nearly obscures Hualālai in the far distance (upper right). USGS photo.

Continuous gas-monitoring site in Moku‘āweoweo Caldera, Mauna Loa V...
August 28, 2015

Continuous gas-monitoring site in Moku‘āweoweo Caldera, Mauna Loa

As magma rises toward Earth's surface, gases dissolved in the molten rock bubble out and escape through surface vents called fumaroles. HVO established sensors atop Mauna Loa in late 2005 to continuously monitor the concentration of carbon dioxide and sulfur dioxide gases and fumarole temperature within Moku‘āweoweo, the summit caldera. These sensors have recorded data

...
Is Mauna Loa gaining weight?...
August 14, 2015

Is Mauna Loa gaining weight?

USGS Hawaiian Volcano Observatory geophysicist Ingrid Johanson measures gravity with a gravimeter on the slope of Mauna Loa with Mauna Kea visible in the background. USGS photo.