Volcanic material in stratosphere over Virginia, Wyoming, and Colorado; source uncertain
St. Helens (Washington, USA)
Lava extrusion adds 5th lobe to crater dome
Kilauea (Hawaii, USA)
Small shallow intrusion under SE part of caldera
Bezymianny (Kamchatka Peninsula, Russia)
Large tephra cloud and lava flow
Pagan (Mariana Islands, central Pacific Ocean)
Renewed explosions on 11 June
Aso (Kyushu, Japan)
30-minute ash and block ejection
Sakura-jima (Kyushu, Japan)
Fewer explosions
Bulusan (Luzon, Philippines)
Earthquake swarm
Mayon (Luzon, Philippines)
Mudflows from typhoon rains
Langila (New Britain Island, Papua New Guinea)
Increased ash emissions, glow, lava fragments
Manam (Bismarck Sea, Papua New Guinea)
Ash emission continues; rumblings
St. Helens (Washington, USA)
Occasional ash plumes to 3 km altitude
Gamkonora (Halmahera, Indonesia)
Tephra ejection; more than 3,500 flee briefly
Kilauea (Hawaii, USA)
Intrusion under S summit area and SW rift zone
Etna (Sicily, Italy)
Ash ejection, probably caused by central crater collapse
Tiatia (Kurile Islands, Russia)
Vapor emission and glow
Langila (New Britain Island, Papua New Guinea)
Vulcanian explosions and glow continue; seismicity intensifies
Manam (Bismarck Sea, Papua New Guinea)
Ash emission continues
Karkar (Offshore New Guinea, Papua New Guinea)
New fumaroles and hot springs
Sakura-jima (Kyushu, Japan)
Explosions decline; seismic and eruptive activity since 1978 summarized
White Island (New Zealand)
Volcanic seismicity declines; no sign of tephra ejection since May
Bulusan (Luzon, Philippines)
No eruption follows earthquake swarm
Mayon (Luzon, Philippines)
Mudflow casualties updated
Turrialba (Costa Rica)
Low-temperature gases collected
Irazú (Costa Rica)
Low-temperature gases collected
Poás (Costa Rica)
Medium-to-high temperature gases collected
Momotombo (Nicaragua)
Medium-to-high temperature gases collected
San Cristobal (Nicaragua)
Medium-to-high temperature gases collected
Atmospheric Effects
Volcanic material below the tropopause over NW North America in mid-July; source unknown
St. Helens (Washington, USA)
Lava extrusion adds new lobe to composite dome
Krafla (Iceland)
Pattern of inflation changes
Asama (Honshu, Japan)
Earthquake swarm but no eruption
Sakura-jima (Kyushu, Japan)
Explosions increase
Kilauea (Hawaii, USA)
More information on SW Rift intrusion
Paluweh(Lesser Sunda Islands, Indonesia)
Incandescent material; seismicity
Langila (New Britain Island, Papua New Guinea)
Ash and incandescent tephra ejection, then explosions and seismicity decline
Manam (Bismarck Sea, Papua New Guinea)
Incandescent lava, glow, sounds
Arenal (Costa Rica)
Lava flows and incandescent tephra; lava dome obstructing active vent deflates
Poás (Costa Rica)
Incandescent fissures; steam explosions; harmonic tremor and shallow discrete events
St. Helens (Washington, USA)
Minor ash emission; slow deformation
Pavlof (Alaska, USA)
Ash clouds; lava flow; seismicity
Shishaldin (Aleutian Islands, USA)
Plumes accompany eruption at nearby Pavlof
Etna (Sicily, Italy)
Collapse in the central crater; ash ejection
Guagua Pichincha (Ecuador)
Small phreatic explosions; felt earthquakes
Colima (western México)
New lava dome in summit crater; activity since 1976 summarized
Paluweh (Lesser Sunda Islands, Indonesia)
Lava dome destoyed; pyroclastic flows
Kavachi (Solomon Islands)
Bubbling and discolored water
Pagan (Mariana Islands, central Pacific Ocean)
New vent in the summit crater
Farallon de Pajaros (Mariana Islands, central Pacific Ocean)
Normal fuming and discolored water
Langila (New Britain Island, Papua New Guinea)
Ashfalls; incandescent tephra; discontinuous tremor
Manam (Bismarck Sea, Papua New Guinea)
Incandescent tephra ejected; ash emission and seismicity decline
White Island (New Zealand)
Little eruptive activity for six months; B-type events increase
Sakura-jima (Kyushu, Japan)
Frequent explosions, mud-like ejection
St. Helens (Washington, USA)
Lava extrusion adds new lobe to composite dome
Krakatau (Indonesia)
Small ash clouds
Langila (New Britain Island, Papua New Guinea)
New lava flow, incandescent tephra, ash emission
Manam (Bismarck Sea, Papua New Guinea)
Incandescent tephra, glow, ash plume
Ruapehu (North Island, New Zealand)
Increased seismicity; lower crater lake temperatures; eruption expected
Sakura-jima (Kyushu, Japan)
Frequent explosions, two incandescent columns
Fukutoku-Okanoba (Volcano Islands, Japan)
Frequent water discoloration observed during January-October 1981
Minami-hiyoshi (Volcano Islands, Japan)
No discolored water seen during January-October 1981
Fukujin (Volcano Islands, Japan)
Water discoloration seen in January 1981, but then none through October
Suwanose-jima (Ryukyu Islands, Japan)
January-August 1981 explosions tabulated
Etna (Sicily, Italy)
Small plumes on satellite images
Soufriere Guadeloupe (Guadeloupe, West Indies)
Temperature, magnetic field stable
Mehetia (French Polynesia, Pacific Ocean)
Several months of increased seismicity
Atmospheric Effects
Aircraft and satellite data on stratospheric ejecta from four eruptions
Krafla (Iceland)
Fissure eruption
Macdonald (south-central Pacific Ocean)
Six submarine eruptions since December 1977
St. Helens (Washington, USA)
Dome expands slowly; rock avalanches
Pagan (Mariana Islands, central Pacific Ocean)
Tephra ejection
Guagua Pichincha (Ecuador)
Minor ash ejection; local earthquakes
Ruapehu (North Island, New Zealand)
Small ash eruption
Langila (New Britain Island, Papua New Guinea)
Eruption column to 6-7 km altitude; nuées ardentes
Manam (Bismarck Sea, Papua New Guinea)
Incandescent tephra; ashfalls
Sakura-jima (Kyushu, Japan)
More frequent explosions; tephra breaks windshields
Suwanose-jima (Ryukyu Islands, Japan)
Three days of explosions
Merapi (Java, Indonesia)
Sixty percent of the summit dome destroyed; hot avalanches
Dieng Volcanic Complex (Java, Indonesia)
Earthquake swarm, but little change in thermal activity
Nyamuragira (DR Congo)
Fissure eruption; lava flow and tephra column
St. Helens (Washington, USA)
Rock avalanches; no significant deformation
Sakura-jima (Kyushu, Japan)
Notable explosions of 1981 tabulated
Ruapehu (North Island, New Zealand)
Small ash eruption; seismicity; possible intrusion
Langila (New Britain Island, Papua New Guinea)
Strong explosions continue; incandescent tephra
Manam (Bismarck Sea, Papua New Guinea)
Explosions and seismicity intensify
Kliuchevskoi (Kamchatka Peninsula, Russia)
Hot spot and plume on satellite images
Tiatia (Kurile Islands, Russia)
Moderate fumarolic activity from the summit crater
Medvezhia (Kurile Islands, Russia)
Intense fumarolic activity from the Kudriavy cone
Kolokol Group (Kurile Islands, Russia)
Weak gas release from the Berg and Trezubetz summit domes
Zavaritski Caldera (Kurile Islands, Russia)
No fumarolic activity
Ketoi (Kurile Islands, Russia)
Intense fumarolic activity on the N slope
Ushishur (Kurile Islands, Russia)
Weak gas release from S part of caldera
Sarychev Peak (Kurile Islands, Russia)
Intensely active fumaroles in center of summit crater
Krafla (Iceland)
Magma reservoirs inflated to pre-eruption level
Etna (Sicily, Italy)
Collapse continues in central crater; ash plumes
Masaya (Nicaragua)
Large white vapor plume and high SO2 emission rates continue
San Cristobal (Nicaragua)
Small irregular white gas plume; incandescence seen
Cerro Negro (Nicaragua)
Small fumarolic region
Telica (Nicaragua)
Continuous white vapor plume with occassional ash
Momotombo (Nicaragua)
Small continuous vapor plume
Arenal (Costa Rica)
Block lava emission continues from summit crater
Poás (Costa Rica)
Bright incandescence seen in cracks; large white plume
Irazú (Costa Rica)
No activity observed