September 19, 2015 Mauna Loa
Routine check of summit cameras
This panorama is from the north rim of Mauna Loa's summit caldera, Mokuʻāweoweo, and shows the thermal camera watching for changes on the caldera floor.
September 17, 2015 Mauna Loa
Mauna Loa - Earthquake and Deformation Data 2010-2015
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 distance across Mauna Loa's summit caldera between 2010 and September 17, 2015. Blue dots indicate the relative distance between two stations that span the summit caldera of Mauna Loa, shown in the map on the upper left. Sustained extension across the caldera started in mid-2014. This extension is one of the indicators of magma infilling a complex reservoir system beneath the summit and upper Southwest Rift Zone.
August 28, 2015 Mauna Loa
Gas monitoring atop 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 Mokuʻāweoweo, the summit caldera. These sensors have recorded data for nearly 10 years, with some ups and downs in temperatures, but no measured change in the gases. On August 28, HVO gas geochemists went to the monitoring site to replace and recalibrate the gas sensors.
January 28, 2014 Mauna Loa
Winter storm deposits snow on Mauna Loa's summit
This Quicktime video shows a time-lapse sequence spanning from dawn to dusk on Tuesday, January 28, using images collected by our webcam near the summit of Mauna Loa Volcano (13,680 ft above sea level). The dawn is sunny with clear views across the summit caldera (Mokuʻāweoweo), but this clear weather soon deteriorates into thick clouds and steady snowfall as a winter storm arrives. This video shows the potential for rapidly changing weather conditions in Hawaiʻi's alpine zones.
January 25, 2010 Mauna Loa
Spectacular views of Mauna Loa's Southwest and Northeast Rift Zones
Left: View looking up Mauna Loa's spectacular Southwest Rift Zone. Puʻu o Keokeo fills the lower half of the photo. The black lava beyond is mostly from 1916 and 1926. The summit of Mauna Loa is in the background. Right: Sulfur, not snow, paints the ground white in the Sulfur Cone area on Mauna Loa's upper Southwest Rift Zone. The summit of Mauna Loa is over the slope of the mountain out of sight to the left in the background.
Left: View from just below the summit of Mauna Loa looking back down the Southwest Rift. The Sulfur Cone is the white area just above center frame. Puʻu o Keokeo is the barely visible bump just above Sulfur Cone at the crest of the Southwest Rift. Right: The 1940 cone, just above center, pokes up above the otherwise relatively flat floor of Mokuʻāweoweo the summit caldera of Mauna Loa. Mauna Kea rises up in the background.
July 31, 2009 Mauna Loa
Spectacular aerial views of Mauna Loa and neighboring volcanoes!
Left: Beautiful weather this morning permitted great views of Mauna Kea, on the right, and Haleakalā, on the neighboring island of Maui, in the distance on the left. The cones in the foreground are along Mauna Loa's north east rift zone. Right: The high point of Mauna Loa, in the background at an elevation of about 13,679 ft, is actually just the highest point along the rim of the steep cliffs that surround Mauna Loa's summit caldera, Mokuʻāweoweo, Dark-colored lava flows of recent vintage (1984) cover the floor of Mokuʻāweoweo. View is looking southwest.
Left: This edge of the cliff above Mokuʻāweoweo, at an elevation of 13,661 feet, is only a few feet lower than Mauna Loa's high point (out of sight to the left). The cliff here is about 600 feet high. Mauna Kea, in the background to the right rises to an elevation of 13,796 feet, barely 100 feet higher the summit of Mauna Loa. Haleakalā, to the left almost 100 miles away and separated from Hawaiʻi by 30 miles of open ocean, rises to 10,023 feet above sea level. Right: This view of Mauna Loa's summit is looking toward the northeast. The east flank of Mauna Kea is to the left, and North Pit, on the northeast end of Mokuʻāweoweo, is straight ahead.
September 21, 2008 Mauna Loa
Comparative views of the 1949 cinder-and-spatter and 1940 vent cones
Left: The 1949 cinder-and-spatter cone (left) and 1940 spatter cone (right) as seen from the floor of Mauna Loa's summit caldera, looking to the southwest. Pāhoehoe flows in the foreground were erupted in 1984. Right: Close-up of the 1949 cinder-and-spatter cone as seen from the floor of Mokuʻāweoweo, Mauna Loa's summit caldera. Pāhoehoe lava visible in the foreground (lower half of photo) was erupted in 1940. Beyond these flows, you can see pāhoehoe flows, spatter, and tephra erupted in 1949.
Left: This view of Mauna Loa's 1940 vent cone, looking to the southwest, shows a fissure that bisected it during the 1984 eruption (crack on the right side of the cone). Pāhoehoe flows and spatter erupted from the 1984 fissure blanket the caldera floor northwest of the cone (foreground). Right: The 1940 cinder-and-spatter cone as seen from the caldera floor looking to the southeast. This cone, which is about 114 m (373 feet) high, was built around the vent as lava spewed from it over a period of 134 days. The dark-colored pāhoehoe flows visible in the foreground were erupted in 1984. Rocky debris on top of the 1984 flows is from small collapses of the steep caldera walls. The largest boulder is about 1 m (3 feet) long.
Left: A close-up view of the 1984 fissure that cut through the southwest side of Mauna Loa's 1940 vent cone. The crack on the right side of the cone is the 1984 fissure. Right: Aerial view of Mauna Loa's upper northeast rift zone near the area where it intersects Mokuʻāweoweo, the summit caldera. Pāhoehoe flows visible in the foreground were erupted in 1942. Distant steep cliffs (right background) are the west wall of the summit caldera.
July 2, 2008 Mauna Loa
Spectacular views of the summit caldera of Mauna Loa
A view of Mokuʻāweoweo, the summit caldera of Mauna Loa, as seen from South Pit (looking to the north-northwest). An eruption in 1940 created the cinder-and-spatter cone visible on the caldera floor (right center). This cone, which is about 114 m (373 feet) high, is the largest cone at Mauna Loa's summit. The cone on the southwest rim of the caldera (left center) was built during an eruption in 1949. The light-brown tephra from that eruption mantles pāhoehoe flows in the foreground.
Left: This aerial view of Mauna Loa's summit shows the cinder-cone and lava flows that were erupted in 1949. The crack extending down the left side of the cone is the northeast-southwest trending 1984 fissure that bisected the southwest flank of the cone during the initial phase of the eruption. Light-brown tephra erupted from the 1949 cone thins to the west. The steep caldera walls north (right) of the cone are 70 m (230 feet) high. Right: An aerial view of the 1940 cinder-and-spatter cone on the floor of Mauna Loa's summit caldera as seen from the southeast. The west wall of the caldera (background) is about 170 m (560 feet) high. Most of the caldera floor around the cone is covered by lava flows erupted in 1984.
May 12, 2005 Mauna Loa
Looking towards Mauna Kea volcano from the Mauna Loa Solar Observatory
Mauna Loa Solar Observtory, with snow-capped Mauna Kea volcano in background.
The Big Island of Hawaiʻi is made up of five volcanoes, Kohala, Mauna Kea, Hualālai, Mauna Loa, and Kīlauea.
Mauna Kea means "White Mountain" in Hawaiian and is Hawaiʻi's tallest volcano. It is considered a dormant volcano, but is likely to erupt again. At least 7 separate vents erupted between 6,000 and 4,000 years ago. For information on Mauna Kea, click here.
February 27, 2002 Mauna Loa
March 15, 2000 Mauna Loa
Rocks ejected during explosive event at summit Mauna Loa Volcano, Hawaiʻi
Left: An under-appreciated and poorly understood aspect of Mauna Loa's eruptive activity is the presence of explosion debris on the east and west sides of the summit caldera. The blocks shown in the photos were ejected sometime during or after the caldera formed, less than 1,300 years ago. The largest blocks are more than 1.5 m in diameter. Most consist of pieces of old lava flows, but some blocks on the west side are coarse grained (gabbro is the official rock name) and probably came from intrusions that cooled slowly enough for minerals to grow large. The blocks were hot when hurled from the caldera, as can be determined by the pattern of cooling cracks within the blocks. Right: Ground and surface water heated to steam is thought to be responsible for many of the explosions at Mauna Loa's lower neighbor, Kīlauea. But, Mauna Loa stands so high that it is hard to imagine that much water was available. Could there have been buried ice lenses large enough to have powered the explosions? Could large snow banks have supplied the water? Or, could the explosions have been driven by carbon dioxide or other gases derived from magma? Much research remains to be done before these questions can be answered. Meanwhile, explosions should be viewed as an infrequent, but nonetheless present, hazard at the top of Earth's largest volcano.
July 6, 1975 Mauna Loa
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 Mokuʻāweoweo, 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 zone activity ended, but fountains on the northwest rift zone continued to erupt until 7:30 p.m. on July 6, when all eruptive activity ceased. This July 6 photo shows eruptive fissures that opened along the Northeast Rift Zone of Mauna Loa and fed voluminous ʻaʻā lava flows that quickly moved down the north flank of the volcano.
June 2, 1950 Mauna Loa
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 ʻaʻā lava flow crossed the main highway on the west coast of the Island of Hawaiʻi and inundated the village of Pahoehoe (all villagers reached safety unharmed, but, for some, it was a close call). Thirty-five minutes later, lava entered the ocean, creating billowy clouds of steam that rose 3,000 m (10,000 ft) into the air. This Mauna Loa eruption destroyed about two dozen structures and cut Highway 11 in three places, burying more than 1.6 km (1 mi) of the road, before ending on June 23. This aerial photo shows the erupting fissure early on the morning of June 2, 1950. The glow from it could be seen all the way to Oʻahu. Photo credit: Air National Guard, 199th Fighter Squadron.
Mauna Loa 1950 Eruption
This aerial photo shows the Kaʻapuna lava flow erupted from Mauna Loa in 1950 as it advanced through the forest at about 3,000 feet elevation on the morning of June 2. This rapidly moving ʻaʻā lava flow traveled from the Southwest Rift Zone vent to the ocean in about 17 hours. Earlier flows from this same eruption reached the ocean in as little as three hours. A narrative of the 1950 Mauna Loa eruption, which began on June 1 and ended on June 23, is posted at http://hvo.wr.usgs.gov/maunaloa/history/50_06_01/. Photo credit: Air National Guard, 199th Fighter Squadron.