Ruiz aerosols remain in stratosphere
Nevado del Ruiz (Colombia)
Ash emission; fine ash to 50 km W
Arenal (Costa Rica)
New lava flow; explosions decrease; tremor continues
Lascar (northern Chile)
Ashfall in Argentina 16 September; ash chemistry
Masaya (Nicaragua)
Collapse and small eruptions from inner crater
Pacaya (Guatemala)
Strong ash emission; lava flows; 600 evacuated
Fuego (Guatemala)
Earthquake swarm; deformation; vapor plume
Santa Maria (western Guatemala)
Rain causes S-flank mudflows, floods
Krafla (Iceland)
Gradual inflation during late 1986, early 1987
Piton de la Fournaise (Reunion Island)
Seismicity, tilt, and summit intrusion
Macdonald (south-central Pacific Ocean)
Acoustic waves from moderate eruption
Kilauea (Hawaii, USA)
Lava enters ocean from underwater tubes and surface flows
White Island (New Zealand)
Ash/block eruptions; inflation; seismicity
Ruapehu (North Island, New Zealand)
Crater lake temperature falls; some tremor
Rabaul (New Britain Island, Papua New Guinea)
August 1985-March 1987 summarized; May seismicity low
Manam (Bismarck Sea, Papua New Guinea)
Strombolian activity
Bagana (Bougainville Island)
Activity declines; vapor emission continues
Kanlaon (Central Philippines)
Sulfate increased in thermal area before ash eruption
Bulusan (Luzon, Philippines)
Seismic swarm and slightly increased steaming
Tokachi (Hokkaido, Japan)
Ground temperature increase; tremor and seismic swarms
Oshima (Izu Islands, Japan)
Earthquake swarm; no new eruptive activity
Sakura-jima (Kyushu, Japan)
Minor ash eruptions but no recorded explosions
Suwanose-jima (Ryukyu Islands, Japan)
Ash eruption
Shiveluch (Kamchatka Peninsula, Russia)
Plume on satellite image
Pavlof (Alaska, USA)
Ash emission; flow; seismic amplitudes increase
Atmospheric Effects
Ruiz aerosols persist in stratosphere
Manam (Bismarck Sea, Papua New Guinea)
Violent Strombolian eruption; pyroclastic flows
Bagana (Bougainville Island)
Lava flow remains active
Rabaul (New Britain Island, Papua New Guinea)
Seismicity, deformation, and tilt low
Macdonald (south-central Pacific Ocean)
Acoustic waves recorded from eruption
White Island (New Zealand)
Explosions weaken; inflation accelerates
Marapi (Sumatra, Indonesia)
Small explosions; ashfall on two cities
Semeru (Java, Indonesia)
Normal Vulcanian activity
Sangeang Api (Lesser Sunda Islands, Indonesia)
Frequent explosions continue
Iliboleng (Lesser Sunda Islands, Indonesia)
Earthquakes increase; 300-m-high plume
Banda Api (Banda Sea, Indonesia)
Small plume observed after large earthquake
Lokon-Empung (Sulawesi, Indonesia)
Two ash explosions
Mahawu (Sulawesi, Indonesia)
Lake volume and temperature increase, seismicity rises
Oshima (Izu Islands, Japan)
Three earthquake swarms; intermittent tremor continues
Bandai (Honshu, Japan)
Earthquake swarm
Sakura-jima (Kyushu, Japan)
Explosions and ash emission continue; gas damages trees
Nevado del Ruiz (Colombia)
Peak 1987 SO2 emission; seismicity declines
Arenal (Costa Rica)
Stronger explosions; ashfalls to 20 km W
Tacaná (Mexico)
Steam output decreases; gas analyses
Kilauea (Hawaii, USA)
Lava flow builds coast, destroys house; inflation resumes
Cleveland (Aleutian Islands, USA)
Lava flow and ash emission from summit crater
Okmok (Aleutian Islands, USA)
Minor ash emission
Akutan (Aleutian Islands, USA)
Summit incandescence; ash and steam emission
Pavlof (Alaska, USA)
Incandescent flow; summit glow; ash emission continues
Atmospheric Effects
New stratospheric layer may be from forest fire smoke
Colima (western México)
Large avalanche from summit lava dome; small A-type events
Tacaná (Mexico)/Guatemala)
Continued minor seismicity and gas emission
Santa Maria (western Guatemala)
Block lava flow into canyon; constant avalanching
Fuego (Guatemala)
Small plume; possible microearthquake swarm
Pacaya (Guatemala)
Strombolian activity, seismicity precede June explosion
Arenal (Costa Rica)
Moderate activity continues; explosions increase
Irazú (Costa Rica)
Crater lake drains
Nevado del Ruiz (Colombia)
Seismicity continues; minor inflation
Kilauea (Hawaii, USA)
Tube system blockage changes shield, lava flows
Cleveland (Aleutian Islands, USA)
Incandescent fountains from summit vent
Okmok (Aleutian Islands, USA)
Minor ash emission
Pavlof (Alaska, USA)
Activity decreases; steam and ash emission
Fukutoku-Okanoba (Volcano Islands, Japan)
Submarine eruptions; floating pumice
Sakura-jima (Kyushu, Japan)
Explosions, ash emission continues
Oshima (Izu Islands, Japan)
Volcanic tremor; small earthquakes below summit
Manam (Bismarck Sea, Papua New Guinea)
Tephra eruption; seismicity decreases
Rabaul (New Britain Island, Papua New Guinea)
Low level seismicity and deformation
Bagana (Bougainville Island)
Vapor emissions continue; no incandescence seen
Semeru (Java, Indonesia)
Glowing rockfall avalanches enter new drainages
Sangeang Api (Lesser Sunda Islands, Indonesia)
Activity continues; plumes to 600 m
Iliboleng (Lesser Sunda Islands, Indonesia)
Volcanic earthquakes decline late in month
Mahawu (Sulawesi, Indonesia)
White plume present, 1977 activity reviewed
Karangetang (Sulawesi, Indonesia)
Small explosions
Atmospheric Effects
New aerosols extend into lower stratosphere
Ol Doinyo Lengai (Tanzania)
Eruptive history January 1983-June 1987
Nyamuragira (DR Congo)
Correction to July 1986 eruption site
Erta Ale (Ethiopia)
Landsat data show two crusted lava lakes
Piton de la Fournaise (Reunion Island)
Lava flows from summit crater
Poás (Costa Rica)
Geyser-like eruptions; crater lake lowers; new fractures
Arenal (Costa Rica)
Strombolian activity and lava flows; explosions decline
Irazú (Costa Rica)
Flank fumarolic activity from two craters
Turrialba (Costa Rica)
Fumarolic activity from two craters
Pacaya (Guatemala)
Lava production resumes; Strombolian activity
Fuego (Guatemala)
Gas emission and microearthquakes
Santa Maria (western Guatemala)
Lava flow from dome; many avalanches; explosions
Tacaná (México)
Fewer microearthquakes
Kilauea (Hawaii, USA)
Lava production continues; deep tremor
Amukta (Aleutian Islands, USA)
Possible source of 10.6-km cloud
Cleveland (Aleutian Islands, USA)
Possible source of 10.6-km cloud; lava flow
Gareloi (Aleutian Islands, USA)
Narrow steaming flow-like feature
Pavlof (Alaska, USA)
Continued ash emission
Shiveluch (Kamchatka Peninsula, Russia)
Ash plumes and base surges from extrusive dome
Fuji (Honshu, Japan)
Earthquake swarm below summit probably tectonic
Sakura-jima (Kyushu, Japan)
Explosions continue
Pagan (Mariana Islands, central Pacific Ocean)
Small eruption cloud; 1981 scoria has flowed into village
Esmeralda Bank (Mariana Islands, central Pacific Ocean)
Bubbling and discolored water
Sorikmarapi (Sumatra, Indonesia)
Seismicity and fumarole temperatures increase
Merapi (Java, Indonesia)
Lava dome growth, but nuées ardentes de avalanche stop
Semeru (Java, Indonesia)
Vulcanian activity continues; nuées ardentes de avalanche
Sangeang Api (Lesser Sunda Islands, Indonesia)
Small explosions continue
Banda Api (Banda Sea, Indonesia)
Local seismicity but no change in volcanic activity
Colo [Una Una] (Sulawesi, Indonesia)
Plume seen on satellite imagery
Mahawu (Sulawesi, Indonesia)
1977 lake data corrected
Rabaul (New Britain Island, Papua New Guinea)
Seismicity declines; deflation in caldera
Manam (Bismarck Sea, Papua New Guinea)
Maps of 30 June eruption products; low-level activity
Bagana (Bougainville Island)
Ash plume; incandescent rockfalls
Ruapehu (North Island, New Zealand)
Crater lake temperature increase; convecting lake water
Deception Island (Antarctica)
Plume on satellite imagery; local seismicity
Atmospheric Effects
Aerosols at 12 km mostly H2SO4 spheres; no new layers
Macdonald (south-central Pacific Ocean)
Eruption jolts research ship; products sampled
Kilauea (Hawaii, USA)
Lava destroys seven more houses
Bagana (Bougainville Island)
Pyroclastic avalanches end 12-year lava flow
Rabaul (New Britain Island, Papua New Guinea)
Low seismicity; subsidence
Manam (Bismarck Sea, Papua New Guinea)
Minor ash emission; night glow from summit
Iliboleng (Lesser Sunda Islands, Indonesia)
Explosion deposits ash on nearby village
Sangeang Api (Lesser Sunda Islands, Indonesia)
Small explosions continue
Karangetang (Sulawesi, Indonesia)
Rumblings, but no more explosions reported
Semeru (Java, Indonesia)
Vulcanian activity continues
White Island (New Zealand)
Ash eruption; tremor and eruption earthquakes
Ruapehu (North Island, New Zealand)
Small hydrothermal eruptions
Oshima (Izu Islands, Japan)
Intermittent volcanic tremor; summit-area earthquakes
Sakura-jima (Kyushu, Japan)
Explosions damage windshields, roofs
Niigata-Yake-yama (Honshu, Japan)
Small ash eruption; fuming
Fukutoku-Okanoba (Volcano Islands, Japan)
Discolored and spouting seawater
Nevado del Ruiz (Colombia)
Small ash emission; strong seismicity continues
Arenal (Costa Rica)
Explosions increase slightly
Pavlof (Alaska, USA)
New ash deposit
Atmospheric Effects
Aerosols over Hawaii, 1974-87, summarized
Ol Doinyo Lengai (Tanzania)
New lava flows flood crater floor
Macdonald (south-central Pacific Ocean)
Explosion seismicity continues; more observations from research vessel
Mauna Loa (Hawaii, USA)
Steady post-1984 reinflation eruption but seismicity low
Kilauea (Hawaii, USA)
Lava flows into ocean
Taal (Luzon, Philippines)
Increase in recorded earthquakes; minor deformation
Oshima (Izu Islands, Japan)
Renewed explosions; ash to 2,500 m; tourists evacuated
Bayonnaise Rocks (Izu Islands, Japan)
Discolored water within 100 km
Sakura-jima (Kyushu, Japan)
Explosions continue; ash plumes; felt airshocks
Kusatsu-Shirane (Honshu, Japan)
Earthquakes increase to five times monthly average
Niigata-Yake-yama (Honshu, Japan)
Increased fume from summit, decrease from flank
Fukutoku-Okanoba (Volcano Islands, Japan)
Pale green discolored water
Ebeko (Kurile Islands, Russia)
Ash ejections to 1 km; steaming fissures form
Bezymianny (Kamchatka Peninsula, Russia)
Rockslide & fumarole activity; plume on NOAA 9 image
Pavlof (Alaska, USA)
Ash-rich explosions; blocks and spatter form flow
Arenal (Costa Rica)
Seismographs record vigorous explosions
Nevado del Ruiz (Colombia)
Small ash emission; seismicity; highest SO2 of 1987
White Island (New Zealand)
Explosions and ash emission; moderate seismicity
Ruapehu (North Island, New Zealand)
Lake temperatures fall; minor inflation
Rabaul (New Britain Island, Papua New Guinea)
Seismicity low; slight subsidence
Manam (Bismarck Sea, Papua New Guinea)
Increased seismicity and vapor emissions; night glow
Bagana (Bougainville Island)
Continuous vapor emissions; weak glow
Langila (New Britain Island, Papua New Guinea)
Single ash emission
Sangeang Api (Lesser Sunda Islands, Indonesia)
Fewer explosions
Iliboleng (Lesser Sunda Islands, Indonesia)
Continued seismicity follows explosion
Semeru (Java, Indonesia)
Vulcanian activity continues
Colo [Una Una] (Sulawesi, Indonesia)
14 July plume may have been weather cloud
Atmospheric Effects
Stratospheric aerosols stable or declining
Oshima (Izu Islands, Japan)
Explosions after increased seismicity and new fumaroles
Piton de la Fournaise (Reunion Island)
New fissure eruptions
Okataina (New Zealand)
Tectonic seismic swarm; no co-seismic deformation
White Island (New Zealand)
Ash emission continues; new vent
Rabaul (New Britain Island, Papua New Guinea)
Slow subsidence continues; seismicity remains low
Langila (New Britain Island, Papua New Guinea)
Weak summit glow; rumbling; minor ash emissions
Manam (Bismarck Sea, Papua New Guinea)
Strombolian activity
Bagana (Bougainville Island)
Vapor emission still moderate-strong; weak glow
Nevado del Ruiz (Colombia)
Seismicity increases; SO2 emission remains high
Arenal (Costa Rica)
Frequent explosions continue to eject ash and blocks
Kilauea (Hawaii, USA)
Lava flows into ocean, destroys house
Pavlof (Alaska, USA)
Dark ash plumes from near-summit vent
Okmok (Aleutian Islands, USA)
Minor ash emission; possible cone growth
Carlisle (Aleutian Islands, USA)
Ash emission observed but site uncertain
Atmospheric Effects
Lowest aerosol values since 1981
Tupungatito (Chile)
Increased summit thermal activity, small ash eruption in January 1986
Estero de Parraguirre (Chile)
50-km-long lahar kills 41 people
Guallatiri (Chile)
Increased fumarolic activity; distant 1985 observation probably of this volcano
Unnamed Crater (Lesser Sunda Islands, Indonesia)
Explosions, then lava plug forms in crater within area of no known historic activity
Marapi (Sumatra, Indonesia)
Many small explosions; light ashfall over W part of island
Merapi (Java, Indonesia)
No lava dome growth from August to November
Semeru (Java, Indonesia)
Continued Vulcanian activity
Sangeang Api (Lesser Sunda Islands, Indonesia)
Eruptive activity continues at steady rate
Sirung (Lesser Sunda Islands, Indonesia)
Fumaroles and crater lake normal after earthquake
Rabaul (New Britain Island, Papua New Guinea)
Seismicity continues to decline
Ulawun (New Britain Island, Papua New Guinea)
Volcanic earthquakes increase; vapor emission
Langila (New Britain Island, Papua New Guinea)
Pale gray plumes; summit glow
Manam (Bismarck Sea, Papua New Guinea)
Vapor emission continues; some deflation; summit glow
Bagana (Bougainville Island)
Strong steam emissions; low seismicity
Bulusan (Luzon, Philippines)
Strong volcanic earthquakes; weak steam emissions
Taal (Luzon, Philippines)
Seismicity abates; thermal activity normal
Ruapehu (North Island, New Zealand)
Declining lake temperature; minor deflation
Sakura-jima (Kyushu, Japan)
Large explosions break windows; blocks burn cars
Akan (Hokkaido, Japan)
Minor ash emission follows increased seismicity
Ebeko (Kurile Islands, Russia)
Explosions continue; minor ashfall
Okmok (Aleutian Islands, USA)
Ash emission continues
Kilauea (Hawaii, USA)
Lava flows into sea, destroys more houses
Arenal (Costa Rica)
Slight increase in explosions
Póas (Costa Rica)
Phreatic activity continues
Pacaya (Guatemala)
Cone destruction and subsequent growth; lava flows
Piton de la Fournaise (Reunion Island)
Lava flows from fissures & tubes
Erta Ale (Ethiopia)
S lava lake remains larger and hotter than N lake
Atmospheric Effects
1985-87 aerosol data from Hawaii summarized
1987
