UPDATED 9:20 am 10-15 Since its first well-documented eruption in 1843, the volcano has erupted 33 times with intervals between eruptions ranging from months to decades. Mauna Loa last erupted in 1984.
Hey my loves, ALOOOHA PUNATICS XO
here is the most recent MAUNA LOA update 10-14-21 7:31 pm from usgs , and I’m working on the Kilauea update now, so stay tuned for your LERZ civilian defense broadcast of 10-15-21 xox
Alert Level: ADVISORY, Color Code: YELLOW
HAWAIIAN VOLCANO OBSERVATORY WEEKLY UPDATE
U.S. Geological Survey
Thursday, October 14, 2021, 9:31 AM HST (Thursday, October 14, 2021, 19:31 UTC)
MAUNA LOA VOLCANO (VNUM #332020)
19°28'30" N 155°36'29" W, Summit Elevation 13681 ft (4170 m)
Current Volcano Alert Level: ADVISORY
Current Aviation Color Code: YELLOW
Activity Summary: Mauna Loa Volcano is not erupting. Rates of seismicity at the summit remain slightly above long-term background levels, but have not changed significantly over the past week. Other monitoring data streams—ground deformation, gas discharge, and visual observations—show no significant changes.
Observations:
During the past week, HVO seismometers recorded 84 small-magnitude earthquakes—all below M3.0—beneath the summit and upper-elevation flanks of Mauna Loa. The majority of these earthquakes occurred at shallow depths less than 8 kilometers (5 miles) below sea level.
Measurements of ground deformation, using Global Positioning System (GPS) instruments, confirm that the surface of the volcano has not moved significantly over the past week.
Gas concentrations and fumarole temperatures at both the summit caldera and at Sulphur Cone on the Southwest Rift Zone remain stable.
Webcam views have shown no changes to the landscape at the Mauna Loa summit or on the lower flanks of the volcano over the past week.
For more information on current monitoring of Mauna Loa Volcano, see: https://www.usgs.gov/volcanoes/mauna-loa/monitoring
These explosive eruptions usually occur when magma moves upward from far below the surface and encounters groundwater. As the lava vaporizes the water, the expanding steam creates enough pressure to break the ground, ejecting volcanic debris high into the air and littering the eruption site with thousands of rocks. The skies darken with ash, and the countryside tens of kilometers (miles) downwind becomes coated in grime.
Kīlauea had violent steam-driven eruptions as recently as 1924, but Mauna Loa has not produced any major explosions in recorded history. Even though an explosive eruption from Mauna Loa has never been witnessed, ample geologic evidence for pre-historic explosive eruptions exists high atop Mauna Loa.
At the summit of Mauna Loa, around Moku`aweoweo caldera, lie several deposits of ancient explosive debris. These deposits rest atop pahoehoe lava flows that spilled out from the top of the volcano around 1,000 to 1,500 years ago. The largest blocks in these deposits are up to 2.2 m (7.2 ft) in diameter and weigh more than 17,000 kg (38,000 lbs).
Compositionally, the explosive debris varies widely. Some rocks are dense, crystalline, and devoid of bubbles, but others are dense, lack large visible crystals, and contain moderate amounts of bubbles. The many different compositions of the debris give the blocks a variety of different colors, from light green to dark red to salt and pepper. Along with differences in composition, chemical interactions with extremely hot fluids during the eruption affected the color and appearance of the debris.
Some of the debris is a type of rock called gabbro, which is entirely made of crystals. Gabbros are usually composed of the mineral plagioclase (a white mineral, at least 50 percent), pyroxene (a black mineral), and olivine (a green mineral). These rocks are also referred to as xenoliths ("xeno" meaning foreign and "lith" meaning rock), in that they did not form during the explosive eruption but instead had already formed and were brought to the surface by the explosions. Since all of the blocks have been exposed to the howling winds and driving snows for hundreds of years, their surfaces are eroded and dull.
The debris lies in four distinct areas around Moku`aweoweo—two around the north and northwest sides of the caldera, one on the southeast rim that envelops the cabin, and a smaller area down the `Ainapo trail. Within each area, the debris is widely scattered, and it becomes less abundant with increasing distance from the rim of Moku`aweoweo. Most of the larger blocks rest on or near the rim of the caldera, but some of the debris lies as far away from Moku`aweoweo as 4 km (2 miles). Preliminary analysis shows that at least three separate explosive events occurred!
Ongoing study of these ejected rocks and ash by HVO scientists will lead to a better understanding of what caused the explosive eruptions—was it really magma interacting with groundwater, or could volcanic gas have been the driver? In addition, we hope to learn how to predict future explosive eruptions, though this is tough business. Detailed analysis of the minerals in the rocky debris will yield clues as to where and how they formed. In addition, a continuing search for any remaining ash around Moku`aweoweo, if successful, could reveal information about the mechanism of the eruptions. Although Mauna Loa silently rests for the time being, it will certainly awaken again and remind us all that the largest volcano in the world dominates our Big Island home.”
Yep. Just like the explosive and intense coming that they only will refer to as such, and the 1800’s.
Background:
Mauna Loa is the largest active volcano on our planet, rising gradually to 4,170 meters (13,681 feet) above sea level. Its long submarine flanks descend an additional 5 kilometers (3 miles) below sea level to the ocean floor. The ocean floor directly beneath Mauna Loa is, in turn, depressed by the volcano's great mass another 8 kilometres (5 miles). This places Mauna Loa's summit about 17,000 meters (56,000 feet) above its base. The enormous volcano covers half of the Island of Hawaiʻi and by itself amounts to about 85 percent of all the other Hawaiian Islands combined.
Eruptions typically start at the summit and, within minutes to months of eruption onset, about half of the eruptions migrate into either the Northeast or Southwest Rift Zone. Since its first well-documented eruption in 1843, the volcano has erupted 33 times with intervals between eruptions ranging from months to decades. Mauna Loa last erupted in 1984.
Mauna Loa eruptions tend to produce voluminous, fast-moving lava flows that can impact communities on the east and west sides of the Island of Hawaiʻi. Since the mid-19th century, the city of Hilo in east Hawaiʻi has been threatened by seven Mauna Loa lava flows. Mauna Loa lava flows have reached the south and west coasts of the island eight times: in 1859, 1868, 1887, 1926, 1919, and three times in 1950.
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