Kliuchevskoi (Kamchatka Peninsula, Russia)

Tephra ejection; lava flow with fountains

Bezymianny (Kamchatka Peninsula, Russia)

Moderate gas and ash emission

Gorely (Kamchatka Peninsula, Russia)

Ash explosions

Villarrica (central Chile)

Lava flow to N foot; lahar; pyroclastic cone collapses

Teahitia (Society Islands, French Polynesia)

Earthquake swarm and probable submarine eruption

Loihi (Hawaii, USA)

Increased seismicity; nine events of magnitude 3 or greater

Kilauea (Hawaii, USA)

Episodes 29-30; fountains to 460 m; heavy tephra fall

Aso (Kyushu, Japan)

Moderate ash emissions continue; volcanic flame on two nights

Sakura-jima (Kyushu, Japan)

Explosions with strong air shocks; 1984 activity summary

Bagana (Bougainville Island)

Bulging dome; ash-laden plume; N lava flow continues

Ulawun (New Britain Island, Papua New Guinea)

Mild Strombolian activity concludes eruptive phase

Campi Flegrei (Italy)

Seismicity declines; slight deflation

St. Helens (Washington, USA)

Activity remains at background levels

Atmospheric Effects

Major stratospheric warming evaporates aerosols

Heard Island (Indian Ocean)

Lava flow from upper S flank vent; plume

Etna (Sicily, Italy)

Seismicity, then Strombolian activity and lava flows from Southeast Crater; ashfall on coast towns

Campi Flegrei (Italy)

Deflation continues and seismicity weak

Rabaul (New Britain Island, Papua New Guinea)

Seismic activity, ground deformation at low levels

Langila (New Britain Island, Papua New Guinea)

Ash clouds and glowing tephra mark new eruptive phase

Bagana (Bougainville Island)

Rockfalls from flank lava flow; strong vapor emission

Karangetang (Sulawesi, Indonesia)

Lava flow from S flank vent

Soputan (Sulawesi, Indonesia)

Plumes from the May and August 1984 eruptions seen on satellite images

Kanlaon (Central Philippines)

Steam and ash eruption follows local seismicity

Mayon (Luzon, Philippines)

Eruption clouds from 23 September seen on satellite images

Sakura-jima (Kyushu, Japan)

Explosion lofts lapilli that break 43 windshields

Santa Maria (western Guatemala)

Gas and ash emissions; seismicity

Arenal (Costa Rica)

Strombolian activity and lava extrusion continue

Kilauea (Hawaii, USA)

30th episode lasts about 21 hours; tephra falls in Hilo

St. Helens (Washington, USA)

Activity at background levels; longest quiet phase since activity began in 1980

Atmospheric Effects

El Chichón aerosols persist over N Hemisphere

Etna (Sicily, Italy)

S-flank fissure eruption preceded by seismicity and tilt

Jan Mayen (northern Atlantic Ocean)

Steam from new subglacial vent in central crater

Erebus (Antarctica)

Explosions continue, ejecting large pumiceous bombs

Home Reef (Tonga Islands, Pacific Ocean)

Barnacle-encrusted pumice found on two islands

Rabaul (New Britain Island, Papua New Guinea)

Moderate seismic and deformation crisis after several months of decreased activity

Manam (Bismarck Sea, Papua New Guinea)

Increased tremor but little change in ash-poor plume

Langila (New Britain Island, Papua New Guinea)

Return to low level of activity

Bagana (Bougainville Island)

Activity declines; vapor emission; occasional glow

Sakura-jima (Kyushu, Japan)

Strong explosions; lapilli cause damage

Aso (Kyushu, Japan)

Moderate ash emission; volcanic flame

Pacaya (Guatemala)

Lava emission in saddle area stops; lava flow and tephra from small cone in MacKenney Crater

Kilauea (Hawaii, USA)

Episode 31; lava flows into subdivision; tephra builds Pu`u `O`o

St. Helens (Washington, USA)

Activity remains at background levels

Atmospheric Effects

El Chichón aerosols continue gradual decline

Etna (Sicily, Italy)

South-flank lava production continues; tremor energy increases

Pacaya (Guatemala)

Strombolian activity ejects scoria and Pele's Hair

Pagan (Mariana Islands, central Pacific Ocean)

Plumes and new lava flow

Karymsky (Kamchatka Peninsula, Russia)

Apparent new lava flow photographed by astronauts

Sakura-jima (Kyushu, Japan)

Vigorous explosions; pyroclastic flow

Aso (Kyushu, Japan)

Moderate tephra emission; new vent

Rabaul (New Britain Island, Papua New Guinea)

Seismicity declines and tilt slows

Manam (Bismarck Sea, Papua New Guinea)

Strong explosions and glow with increased seismicity

Kilauea (Hawaii, USA)

Episode 32 of 1983-85 middle E Rift Zone eruption

St. Helens (Washington, USA)

Activity at background levels; magnetic data

Atmospheric Effects

Fewer stratospheric aerosols remain over low latitudes

Soputan (Sulawesi, Indonesia)

Seven-hour tephra eruption; jumbo jet flies through plume

Ruapehu (North Island, New Zealand)

Hydrothermal eruptions accompany seismic activity

Piton de la Fournaise (Reunion Island)

Eruption with premonitory seismicity

Etna (Sicily, Italy)

Lava flows toward SW and SE; strong gas and vapor emissions

Nevado del Ruiz (Colombia)

Increased seismicity and abnormal fumarolic activity

Tecapa (El Salvador)

Earthquake swarm at historically inactive volcano

Masaya (Nicaragua)

Small ash eruptions

Concepcion (Nicaragua)

Small ash eruptions

Momotombo (Nicaragua)

Continued high fumarole temperatures

St. Helens (Washington, USA)

Strong seismicity accompanies major dome-building episode

Kilauea (Hawaii, USA)

Summit inflation and low-level harmonic tremor continue; episode 33 of 1983-85 eruption

Atmospheric Effects

El Chichón aerosols persist over low and mid latitudes

Piton de la Fournaise (Reunion Island)

Fissure eruption follows seismicity and deformation

St. Helens (Washington, USA)

Activity returns to background levels

Kilauea (Hawaii, USA)

Episodes 33 and 34; aa lava flows SE

Etna (Sicily, Italy)

Continued S-flank lava production

Vulcano (Italy)

Microearthquake swarm and slight uplift

Aso (Kyushu, Japan)

Ejection of ash and incandescent tephra

Sakura-jima (Kyushu, Japan)

Explosive activity and eathquakes decline

Tokachi (Hokkaido, Japan)

Hot water ejected; new 10-15 m fissure forms

Manam (Bismarck Sea, Papua New Guinea)

Ash emission and seismicity

Rabaul (New Britain Island, Papua New Guinea)

Regional earthquakes cause caldera swarm

Langila (New Britain Island, Papua New Guinea)

Ash emission and glow mark new phase of activity

Tinakula (Solomon Islands)

Vapor and ash emissions

Ruapehu (North Island, New Zealand)

Hydrothermal eruptions and seismicity

Atmospheric Effects

El Chichón aerosols persist; tropospheric layers may be smoke from forest fires

Sangeang Api (Lesser Sunda Islands, Indonesia)

Explosions eject tephra, lava flow; island evacuated

Aso (Kyushu, Japan)

Ash emision ends

Sakura-jima (Kyushu, Japan)

Frequent explosions; tephra damages nearby towns

Tokachi (Hokkaido, Japan)

Two new vents eject hot water, burning sulfur

Suwanose-jima (Ryukyu Islands, Japan)

Explosions resume; 2.5 km plume; ashfall 25 km SE

Rabaul (New Britain Island, Papua New Guinea)

3 July earthquake causes caldera deformation

Langila (New Britain Island, Papua New Guinea)

Stronger Vulcanian explosions

Manam (Bismarck Sea, Papua New Guinea)

Explosions and seismicity increase, then decline

Ruapehu (North Island, New Zealand)

Hydrothermal activity ceases; lake temperatures drop

Piton de la Fournaise (Reunion Island)

Intrusion E of the summit; lava production resumes a month later

Etna (Sicily, Italy)

Four-month eruption ends in mid-July

Nevado del Ruiz (Colombia)

Fumarolic activity increases; ash emissions

Arenal (Costa Rica)

Lava extrusion

Poás (Costa Rica)

Fumarole temperatures drop

Irazú (Costa Rica)

Gas emission

Turrialba (Costa Rica)

Gas emission

Kilauea (Hawaii, USA)

Continuing lava production from new fissures uprift of active vent

St. Helens (Washington, USA)

Activity at background levels

Atmospheric Effects

Sratospheric aerosols from El Chichón persist

Piton de la Fournaise (Reunion Island)

Fissure activity resumes after 5-day hiatus

Oku Volcanic Field (Cameroon)

Fatal 1984 gas emission may have been caused by sudden release of dissolved CO₂, not volcanic activity

Etna (Sicily, Italy)

Map of 1985 lavas

Sangeang Api (Lesser Sunda Islands, Indonesia)

Eruption declines; 4.5 km lava flow

Semeru (Java, Indonesia)

Two-year eruption continues

Rabaul (New Britain Island, Papua New Guinea)

Seismicity declines to pre-crisis levels; tilt slows

Langila (New Britain Island, Papua New Guinea)

Two episodes of explosions, earthquakes and tremor

Manam (Bismarck Sea, Papua New Guinea)

Activity declines; ash emission; weaker seismicity

St. Helens (Washington, USA)

Activity remains at background levels

Kilauea (Hawaii, USA)

Fissure activity ends; new episode three weeks later

Nevado del Ruiz (Colombia)

Ash emission

San Cristóbal (Nicaragua)

Plume sighted from space shuttle

Masaya (Nicaragua)

400 km plume sighted

Atmospheric Effects

Aerosol data similar over Alaska and lower latitudes   

Nevado del Ruiz (Colombia)

Phreatic activity and strong seismicity decline in October

Supply Reef (Mariana Islands, central Pacific Ocean)

Discolored water but no eruption plume

Kanlaon (Central Philippines)

Small ash eruption with seismicity

Sangeang Api (Lesser Sunda Islands, Indonesia)

30 July eruption plume seen on satellite images

Rabaul (New Britain Island, Papua New Guinea)

Seismic activity declines; deformation slows

Langila (New Britain Island, Papua New Guinea)

Stronger explosions; ashfall to 30 km

Manam (Bismarck Sea, Papua New Guinea)

Weak ash emission; seismicity at low levels

Umboi (Offshore New Guinea, Papua New Guinea)

Seismicity; subsidence in flank thermal area

Niuafo`ou (Tonga Islands, Pacific Ocean)

Earthquake swarm and pumice eruption in caldera lake

Ruapehu (North Island, New Zealand)

Crater lake temperature drops 10°C

Piton de la Fournaise (Reunion Island)

Fissure eruption follows inflation and earthquake swarm

Kilauea (Hawaii, USA)

Episode 37 of the 1983-85 East Rift Zone eruption

St. Helens (Washington, USA)

Activity at background levels

Atmospheric Effects