Soputan (Sulawesi, Indonesia)
Tephra eruption
Rabaul (New Britain Island, Papua New Guinea)
Seismicity declines; two earthquake swarms, one crisis
Manam (Bismarck Sea, Papua New Guinea)
Strombolian activity decreases at mid-month
Langila (New Britain Island, Papua New Guinea)
Intermittent ash emission; three Vulcanian explosions
Kliuchevskoi (Kamchatka Peninsula, Russia)
Strombolian activity builds cinder cone; lava flow
Shiveluch (Kamchatka Peninsula, Russia)
Small ash ejection; no change to lava dome
Etna (Sicily, Italy)
Continued lava production; Strombolian activity
El Misti (Perú)
Increased vapor emission
Sakura-jima (Kyushu, Japan)
Explosive activity continues at high level; debris flows
Kaitoku Seamount (Izu Islands, Japan)
Discolored water; floating lapilli; formal name
Kilauea (Hawaii, USA)
19th and 20th episodes; gas-piston activity
St. Helens (Washington, USA)
Explosions from dome; plumes & snow/water flows
Veniaminof (Alaska, USA)
Vapor plumes but no ash or incandescence
Atmospheric Effects
Volcanic aerosols remain in stratosphere
Merapi (Java, Indonesia)
Explosions, nuées ardentes, lahars; 1,000 evacuated
Tinakula (Solomon Islands)
Tephra ejection; W flank submarine cone recognized
Rabaul (New Britain Island, Papua New Guinea)
Seismicity declines; deformation continues
Manam (Bismarck Sea, Papua New Guinea)
Stombolian activity; debris avalanches
Langila (New Britain Island, Papua New Guinea)
Occasional ash emission; seismicity weak
Campi Flegrei (Italy)
Seismicity and uplift continue; socio-economic impact discussed; increased submarine fumarolic activity
Etna (Sicily, Italy)
Explosions and lava production continue from Southeast Crater; central crater explosions
Kilauea (Hawaii, USA)
Episodes 20-22; highest lava fountains of 1983-84 eruption
St. Helens (Washington, USA)
New lobe extruded into notch in dome's W flank
Atmospheric Effects
Atmospheric turbidity over Japan declines gradually from late 1982 to early 1983 peak; lidar shows persistent aerosols
Kilauea (Hawaii, USA)
Episodes 22-23 of 1983-84 E Rift Zone eruption
St. Helens (Washington, USA)
Deformation, seismicity, and SO2 emission drop
Arenal (Costa Rica)
Lava production slows as strong tephra ejection begins
Llaima (central Chile)
Dense columns of dark ash emitted from crater
Rabaul (New Britain Island, Papua New Guinea)
Seismicity declines; deformation increases
Manam (Bismarck Sea, Papua New Guinea)
Strombolian activity; frequent debris avalanches
Home Reef (Tonga Islands, Pacific Ocean)
Large pumice rafts in Fiji area from March eruption
Etna (Sicily, Italy)
Lava production and Strombolian activity continue from Southeast Crater; strong explosions from Central and Northeast craters
Atmospheric Effects
El Chichón aerosols persist in stratosphere
Kliuchevskoi (Kamchatka Peninsula, Russia)
Tephra ejection; lava flows; lahars
Mayon (Luzon, Philippines)
Eruption clouds to 15 km; pyroclastic flows; lava flows
Soputan (Sulawesi, Indonesia)
Ash eruption follows local seismicity
Karangetang (Sulawesi, Indonesia)
Tephra ejection, lava flows, lahars; 20,000 evacuated
Rabaul (New Britain Island, Papua New Guinea)
Earthquake swarms and slow inflation continue
Manam (Bismarck Sea, Papua New Guinea)
Vulcanian explosions; glowing debris avalanches
Ulawun (New Britain Island, Papua New Guinea)
Increased seismicity, then small ash clouds and glow
Bagana (Bougainville Island)
Lava production continues; SO2-rich plume
Langila (New Britain Island, Papua New Guinea)
Occasional ash emission; seismicity weak
Home Reef (Tonga Islands, Pacific Ocean)
Pumice from March-April eruption continues to drift N and W
Krafla (Iceland)
Eruption from 8.5-km fissure
Etna (Sicily, Italy)
Lava production and ash emission continue
Oku Volcanic Field (Cameroon)
Poisonous gas from Lake Monoun explosion kills 37
Pacaya (Guatemala)
Summit-area lava production continues
St. Helens (Washington, USA)
Intense deformation, then extrusion of new lobe
Long Valley (California, USA)
Seismicity at relatively low level and inflation
Kilauea (Hawaii, USA)
Episode 24; high fountains; thin tephra blanket
Veniaminof (Alaska, USA)
Vapor plumes, roaring noise, and felt earthquakes
Atmospheric Effects
10 years of lidar data from Virginia summarized
Erebus (Antarctica)
Vigorous explosions, clouds, and incandescent tephra
Mayon (Luzon, Philippines)
Explosive activity reintensifies; 73,000 evacuated
Karangetang (Sulawesi, Indonesia)
Seismicity and minor tephra emission since January; ash column and nuées ardentes in September
Home Reef (Tonga Islands, Pacific Ocean)
Pumice from March eruption found 1,300 km to the WSW
Ulawun (New Britain Island, Papua New Guinea)
Mild Strombolian eruption
Rabaul (New Britain Island, Papua New Guinea)
Seismicity, ground deformation rates decline
Manam (Bismarck Sea, Papua New Guinea)
Ash-laden emissions, incandescence
Unzen (Kyushu, Japan)
Earthquake swarm
Campi Flegrei (Italy)
More M > 3 events with wider distribution, but seismic energy release unchanged and uplift slows
Etna (Sicily, Italy)
Lava flows, Strombolian activity and ash emission
Kilauea (Hawaii, USA)
Episode 25; highest fountains of 1983-84 eruption; tephra
St. Helens (Washington, USA)
New lobe in collapse zone on composite dome
Villarrica (central Chile)
Brief ash eruption; increased seismicity
Atmospheric Effects
Two years of lidar data from Germany summarized
Etna (Sicily, Italy)
Earthquake swarm starts as lava production ends
Krafla (Iceland)
Satellites detect SO2-rich plume from September eruption
Erebus (Antarctica)
Large pumiceous bombs; lava lake frozen and uplifted
Bezymianny (Kamchatka Peninsula, Russia)
Ash cloud; pyroclastic flows; part of dome destroyed
Home Reef (Tonga Islands, Pacific Ocean)
Ships steam through pumice SE of Fiji
Rabaul (New Britain Island, Papua New Guinea)
Large earthquake swarm accompanied by rapid uplift
Bagana (Bougainville Island)
Lava flow continues; earthquake swarm
Balbi (Bougainville Island)
Boiling mud, active fumaroles and solfataras
Loloru (Bougainville Island)
Solfataras active on dome and flank
Aso (Kyushu, Japan)
Block and ash ejection from fumarole
Kaitoku Seamount (Izu Islands, Japan)
Discolored water after 3 months of quiet
Kilauea (Hawaii, USA)
Episode 26; shortest of 1983-84 eruption
St. Helens (Washington, USA)
Deformation, seismicity, and gas emission low
Ol Doinyo Lengai (Tanzania)
Fumarolic activity
Atmospheric Effects
Lidar data from Italy and Germany
Villarrica (central Chile)
Lava carves channels in ice; bulge on opposite flank
Arenal (Costa Rica)
Strombolian activity and lava extrusion continue
Campi Flegrei (Italy)
Uplift stops in October, but resumes in November
Etna (Sicily, Italy)
Occasional ash emission; flank seismicity continues
Krafla (Iceland)
End of eruption described; tilt data; lava flows mapped
Rabaul (New Britain Island, Papua New Guinea)
Activity declines; alert reduced to Stage 1
Bagana (Bougainville Island)
Lava dome grows & spawns avalanches; seismicity builds
Manam (Bismarck Sea, Papua New Guinea)
Ash-laden emissions; seismicity declines
Ulawun (New Britain Island, Papua New Guinea)
Seismicity increases; vapor emission
Langila (New Britain Island, Papua New Guinea)
Occasional ash emission; seismicity low
Marapi (Sumatra, Indonesia)
Small plumes
Veniaminof (Alaska, USA)
Activity resumes; ash plumes to about 5 km altitude
Kilauea (Hawaii, USA)
Episodes 27 and 28 of 1983-84 middle E Rift Zone eruption
St. Helens (Washington, USA)
Seismicity, SO2 emission, and deformation weak
Atmospheric Effects
Aerosols increase over Italy but decline over Hawaii
Jan Mayen (northern Atlantic Ocean)
Eruption on NE flank, lava flows reach sea
Veniaminof (Alaska, USA)
Tremor accompanied November ash ejection; activity declines
St. Helens (Washington, USA)
Activity remains at background levels
Kilauea (Hawaii, USA)
Episodes 28 and 29 are one-day eruptions with fountains to 450 m
Arenal (Costa Rica)
Explosions; ashfall; lava flows remain in summit area
Poás (Costa Rica)
Fumaroles active, but temperatures lower
Aso (Kyushu, Japan)
Emission of ash containing fresh magma
Sakura-jima (Kyushu, Japan)
Summary of 1984 explosions and damage
Ulawun (New Britain Island, Papua New Guinea)
Incandescent tephra from lava mound; seismicity builds
Rabaul (New Britain Island, Papua New Guinea)
Seismicity decreases; moderate deformation persists
Bagana (Bougainville Island)
Lava extrusion and avalanches from dome; new fumaroles
Atmospheric Effects
Strong twilight colors resume over England