A volcano is a rupture in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface. The process that forms volcanoes is called volcanism.
Mauna Loa is one of five volcanoes that form the Island of Hawaii in the U.S. state of Hawaii in the Pacific Ocean. Mauna Loa is Earth's largest active volcano by both mass and volume. It was historically considered to be the largest volcano on Earth until Tamu Massif was discovered to be larger. Mauna Loa is a shield volcano with relatively gentle slopes, and a volume estimated at 18,000 cubic miles (75,000 km3), although its peak is about 125 feet (38 m) lower than that of its neighbor, Mauna Kea. Lava eruptions from Mauna Loa are silica-poor and very fluid, and tend to be non-explosive.
Volcanology is the study of volcanoes, lava, magma and related geological, geophysical and geochemical phenomena (volcanism). The term volcanology is derived from the Latin word vulcan. Vulcan was the ancient Roman god of fire.
An accelerometer is a device that measures the proper acceleration of an object. Proper acceleration is the acceleration of the object relative to an observer who is in free fall. Proper acceleration is different from coordinate acceleration, which is acceleration with respect to a given coordinate system, which may or may not be accelerating. For example, an accelerometer at rest on the surface of the Earth will measure an acceleration due to Earth's gravity straight upwards of about g ≈ 9.81 m/s2. By contrast, an accelerometer that is in free fall will measure zero acceleration.
Kīlauea is an active shield volcano in the Hawaiian Islands. It is located along the southeastern shore of Hawaii Island. The volcano is between 210,000 and 280,000 years old and grew above sea level about 100,000 years ago. Since the islands were settled, it has been the most active of the five volcanoes that together form the island and among the most active volcanoes on Earth. The most recent eruption occurred in September 2024.
A spirit level, bubble level, or simply a level, is an instrument designed to indicate whether a surface is horizontal (level) or vertical (plumb). Two basic designs exist: tubular and bull's eye . Different types of spirit levels may be used by carpenters, stonemasons, bricklayers, other building trades workers, surveyors, millwrights and other metalworkers, and in some photographic or videographic work.
The Hawaiian Volcano Observatory (HVO) is an agency of the U.S. Geological Survey (USGS) and one of five volcano observatories operating under the USGS Volcano Hazards Program. Based in Hilo, Hawaii, the observatory monitors six Hawaiian volcanoes: Kīlauea, Mauna Loa, Kamaʻehuakanaloa, Hualālai, Mauna Kea, and Haleakalā, of which, Kīlauea and Mauna Loa are the most active. The observatory has a worldwide reputation as a leader in the study of active volcanism. Due to the relatively non-explosive nature of Kīlauea's volcanic eruptions for many years, scientists have generally been able to study ongoing eruptions in proximity without being in extreme danger.
An inclinometer or clinometer is an instrument used for measuring angles of slope, elevation, or depression of an object with respect to gravity's direction. It is also known as a tilt indicator, tilt sensor, tilt meter, slope alert, slope gauge, gradient meter, gradiometer, level gauge, level meter, declinometer, and pitch & roll indicator. Clinometers measure both inclines and declines using three different units of measure: degrees, percentage points, and topos. The astrolabe is an example of an inclinometer that was used for celestial navigation and location of astronomical objects from ancient times to the Renaissance.
Volcanic gases are gases given off by active volcanoes. These include gases trapped in cavities (vesicles) in volcanic rocks, dissolved or dissociated gases in magma and lava, or gases emanating from lava, from volcanic craters or vents. Volcanic gases can also be emitted through groundwater heated by volcanic action.
Prediction of volcanic activity, and volcanic eruption forecasting, is an interdisciplinary monitoring and research effort to predict the time and severity of a volcano's eruption. Of particular importance is the prediction of hazardous eruptions that could lead to catastrophic loss of life, property, and disruption of human activities.
Kīlauea Iki is a pit crater that is next to the main summit caldera of Kīlauea on the island of Hawaiʻi in the Hawaiian Islands. It is known for its eruption in 1959 that started on November 14 and ended on December 20, producing lava fountaining up to 1900 feet and a lava lake in the crater. Today, the surface of the lava lake has cooled and it is now a popular hiking destination to view the aftermath of an eruption.
Halemaʻumaʻu is a pit crater within the much larger Kīlauea Caldera at the summit of Kīlauea volcano on island of Hawaiʻi. The roughly circular crater was 770 meters (2,530 ft) x 900 m (2,950 ft) before collapses that roughly doubled the size of the crater after May 3, 2018. Following the collapses of 2018, the bottom of Halemaʻumaʻu was roughly 600 m (2,000 ft) below the caldera floor. Halemaʻumaʻu is home to Pele, goddess of fire and volcanoes, according to the traditions of Hawaiian religion. Halemaʻumaʻu means "house of the ʻāmaʻu fern".
Lava is molten or partially molten rock (magma) that has been expelled from the interior of a terrestrial planet or a moon onto its surface. Lava may be erupted at a volcano or through a fracture in the crust, on land or underwater, usually at temperatures from 800 to 1,200 °C. The volcanic rock resulting from subsequent cooling is also often called lava.
Angular rate sensors, ARS, are devices that directly measure angular rate, without integration in conditioning electronics. Gyroscopes also measure angular rate. Generally gyroscopes are able to measure a constant rotation rate, while rate sensors also include devices with a low cut off frequency that is other than zero.
The sliding criterion (discontinuity) is a tool to estimate easily the shear strength properties of a discontinuity in a rock mass based on visual and tactile characterization of the discontinuity. The shear strength of a discontinuity is important in, for example, tunnel, foundation, or slope engineering, but also stability of natural slopes is often governed by the shear strength along discontinuities.
The 2018 lower Puna eruption was a volcanic event on the island of Hawaiʻi, on Kīlauea volcano's East Rift Zone that began on May 3, 2018. It is related to the larger eruption of Kīlauea that began on January 3, 1983, though some volcanologists and USGS scientists have discussed whether to classify it as a new eruption. Outbreaks of lava fountains up to 300 feet (90 m) high, lava flows, and volcanic gas in the Leilani Estates subdivision were preceded by earthquakes and ground deformation that created cracks in the roads.
In volcanology, deformation refers to the change in the shape of a volcano or the surrounding landscape due to the movement of magma. This can be in the form of inflation, which is a response to pressurization, or deflation, which is a response to depressurization. Inflation is represented by swelling of the ground surface, a volcanic edifice, or a subsurface magma body. It can be caused by magma accumulation, exsolution of volatiles, geothermal processes, heating, and tectonic compression. Deflation is represented by shrinking of the ground surface, a volcanic edifice, or a subsurface magma body. It can be caused by magma withdrawal, volatile escape, thermal contraction, phase changes during crystallization, and tectonic extension. Deformation is a key indicator of pre-eruptive unrest at many active volcanoes, but deformation signals must be used in combination with other eruption indicators for forecasting reliability.
A tilt detector or tilt indicator is a device which indicates whether a tilt has occurred. Tilt detectors can be used on shipments of tilt sensible items to indicate whether a potentially damaging tilt have occurred. They are also used in the field of electronics or automotive on some models to detect if a change in vehicle inclination has occurred.
The 2022 eruption of Mauna Loa was an episode of eruptive volcanic activity at Mauna Loa, the world's largest active volcano, located on Hawaiʻi island, Hawaiʻi. Mauna Loa began to erupt shortly before midnight HST on November 27, 2022, when lava flows emerged from fissure vents in Moku‘āweoweo. It marked the first eruption at the volcano in 38 years. The eruption ended on December 13, 2022, after more than two weeks.
