GEL 1 Lecture Notes - Lecture 15: Yellowstone Hotspot, Oceanic Crust, Main Sequence
Example of major volcanic eruptions, Pompeii, Krakatoa, Tambora, Yellowstone (know the
dates)
Recent Hawaii Volcanism
●eruption starting last Thursday
●Lava erupting from old and new vents
○Lava "fountaining" as it shoots 100m+ in the air
■current vents that are fountains are not stable
●old previously inactive fissures and new fissures springing up
○Expected to pass 350m height as vents solidify
■no preferred lava path
■up to 1000 feet
●Part of main sequence of eruption
●Unusual because of distance of fissures from main eruptive center
○vents are also very diffuse, diverse
○no one localized group of fissures
●More ash than typical Hot Spot volcanic eruption
○(mafic eruptions are not known for very volatile explosive eruptions)
○pretty typical eruption despite fissures being unusual
■relatively similar amount of volatiles compared to other mafic eruptions
○hypotheses on why there's more ash:
■magma incorporating part of oceanic plate
■transport of magma along island and melting other material?
●Ash sources:
○main volcano: some
○mostly from fires
○height not extreme
■still in troposphere (lower atmosphere)
■flight impacts are mostly local (island to island)
●long flights are in stratosphere
○most pictures show steam, not ash
●Aa Aa lava
Hawaii Earthquake
●5.6 magnitude, followed by 6.9 magnitude Friday morning
○5km depth
○shallow earthquakes, felt almost everywhere on hawaii
○buildings didn't break
●previously active faults
○last known earthquake 1975
●triggered further fissure openings
Document Summary
Example of major volcanic eruptions, pompeii, krakatoa, tambora, yellowstone (know the dates) Lava erupting from old and new vents. Lava fountaining as it shoots 100m+ in the air. Current vents that are fountains are not stable. Old previously inactive fissures and new fissures springing up. Expected to pass 350m height as vents solidify. Unusual because of distance of fissures from main eruptive center. More ash than typical hot spot volcanic eruption. (mafic eruptions are not known for very volatile explosive eruptions) Pretty typical eruption despite fissures being unusual. Relatively similar amount of volatiles compared to other mafic eruptions. Flight impacts are mostly local (island to island) 5. 6 magnitude, followed by 6. 9 magnitude friday morning. Shallow earthquakes, felt almost everywhere on hawaii. Regions of permanently established mud bc there is so much groundwater and steam. Algal bloom and so4 makes colors in the pool. High-silica volcanism due to heat-transfer melting and assimilation of high-silica.
