| Volcanic center
(Time interval evaluated) (Reference) |
of major volcanic centers (Time interval evaluated shown in parentheses for each volcano, and much of these data resulted from this study; other references are cited) |
Most recent eruption | Most probable future potential hazard
(Based on consideration of size, frequency, and severity of event.) |
||||||
| Lava Flows and cinder cones | Domes | Tephra | Pyroclastic flows | Blasts and pyroclastic surges | Debris avalanches and debris flows | ||||
| Mount Shasta
(10,000 years) (Christianson, 1985; Miller, 1978; Miller, 1980) |
Many lava flows and one cinder cone erupted at several vents between 10,000 and about 2,000 years ago. | Two domes formed between about 10,000 and 9,000 years ago; one formed during the last about 2,000 years. | Two tephra eruptions of small volume between about 10,000 and 9,000 years ago; probably volume 0.001-0.1 cubic kilometers. | Many pyroclastic flows down all sides of the volcano; some traveled greater than or equal to 20 kilometers from summit. | None recognized. | Many debris flows down all sides of volcano; many reached more than 30 kilometers from volcano; one reached more than 40 kilometers from volcano. | Small pyroclastic flows, associated ash clouds and debris
flows about 200 carbon-14 years ago
(Miller, 1980). |
Formation of large pyroclastic flows and debris flows. | |
| Medicine Lake Highland Region |
Rhyolite center
(1,500 years) (Chesterman, 1955; Fink and Pollard, 1983; Heiken, 1978; Ives and others, 1964, 1967; Mertzman, 1977) |
At least four lava flows during the last 1,500 years. | Many small silicic domes formed within the last 1,500 years. | Two tephra eruptions of small volume during the last 1,500 years; one slightly older; probable volume 0.05-0.1 cubic kilometers. | None recognized. | None recognized. | None recognized. | Lava flows erupted within the last 1,500 years
(Heiken, 1978). |
Formation of relatively small pyroclastic flows; eruption of tephra. |
| Basalt field
(10,000 years) (Finch, 1933) |
At least 15 lava flows and (or) cinder cones within about the last 10,000 years. | None recognized. | Small volumes of mafic tephra erupted with cinder cones and flows. | None recognized. | None recognized. | None recognized. | Several lava flows probably erupted during the
last few hundred years
(Finch, 1933). |
Formation of cinder cones, small volumes of tephra, and lava flows. | |
| Lassen Peak Region | Lassen area dacites
(12,000 years) (Clynne, 1985; Crandell and others, 1974; Day and Allen, 1925; Heath, 1959; Rubin and Alexander, 1960) |
At least one small lava flow in A.D. 1915. | At least eight silicic domes within the last 12,000 years; four between about 12,000 and 11,000 years; three about 1,000 years ago; one about 350 years ago. | Tephra eruption about 1,100 years ago. | Two pyroclastic flows between about 12,000 and 11,000 years ago; three pyroclastic flows about 1,100 years ago; two pyroclastic flows about 300 years ago. | Two small directed blasts (or pyroclastic flows) in A.D.1915; effects extend to distance of 5 kilometers from summit. | Dozens of debris flows were generated during eruptions at Lassen Peak dome about 11,000 years ago; several debris avalanches about 300 years ago; two small debris flows in A.D.1915. | Lava flow, tephra fall, hot debris flows, and two
small blasts in A.D.1914-1917
(Clynne, 1985; Day and Allen, 1925). |
Formation of pyroclastic flows; small to moderate-size debris flows. |
| Basalt field
(10,000 years) (Anderson, 1940; Finch, 1937; Williams, 1928) |
Eruption of more than 20 mafic centers producing lava flows and (or) cinder cones during the last 10,000 years. | None recognized. | Small volumes of mafic tephra erupted at many centers during Holocene time. About 80 square kilometers covered with ash from Cinder Cone about 400 years ago. | None recognized. | None recognized. | None recognized. | Lava flows, tephra, and cinder cone erupted in
A.D.1851
(Clynne, 1985; Finch, 1937; Williams, 1928). |
Formation of cinder cones, small volumes of tephra, and lava flows. | |
| Clear Lake
(10,000 years) (Berry and others, 1976; Hearn and others, 1976; Sims and Rymer, 1975) |
None recognized. | None recognized. | Numerous mafic tephras were erupted during phreato-magmatic eruptions as recently as about 10,000 years ago. | None recognized. | Numerous phreatic eruptions, hydromagmatic explosions, and base-surge events. | None recognized. | Mafic tephra from phreatomagmatic eruption about
10,000 years ago
(Sims and Rymer, 1975). |
Phreatic and phreatomagmatic explosions, base surges, and small-volume tephra eruptions. | |
| Mono Lake - Long Valley Area | Silicic vents
(10,000 years) (Bailey and others, 1976; Dalrymple, 1967; Mankinen and others, 1986; Miller, 1985; Miller and others, 1982; Reinhart and Huber 1965; Tadduci and others, 1968; Wood, 1983) |
Many silicic lava flows erupted at numerous vents between 1,000 years and about 500 years ago; possible flows younger than 500 years B.P. | Many silicic domes erupted at numerous vents between 10,000 years ago and about 500 years ago. | Many silicic tephras erupted from numerous vents; volumes ranged from more than 0.02 cubic kilometers to less than 0.2 cubic kilometers. | Many pyroclastic flows from numerous vents. Some have flowed 10-15 kilometers from vents. | Many phreatic, phreatomagmatic and pyroclastic surge events have occurred at numerous vents. | Small debris flows have originated at several vents. | A series of explosive magmatic and phreatic
eruptions and emplacement of lava flows occurred at several vents at the
Inyo volcanoes about 550 years ago
(Miller, 1983; 1985; Miller and others, 1982; Wood, 1983). |
Small- to moderate- volume silicic pyroclastic eruptions that will form pyroclastic flows and small to moderate volumes of tephra. |
| Mafic vents
(13,000 years) (Bailey and others, 1976; Lajoie, 1968) |
Sublacustrine mafic eruptions in Mono Lake about 13,000 years ago; eruption of cinder cones and flows at two vents 1,200 to 5,000 years ago. | None recognized. | Mafic cinders erupted at two vents 1,200 to about 5,000 years ago. | None recognized. | None recognized. | None recognized. | Mafic cinder cone and lava flow eruptions at two
vents 1,200 to about 5,000 years ago
(Miller, this report). |
Formation of cinder cones, small volumes of tephra, and lava flows; phreatic explosions. | |
| Amboy Crater - Lavic Lake basalt fields
(about 10,000 years) |
Several mafic lava flows and cinder cones from several vents during last approximately 10,000 years. | None recognized. | Mafic tephra erupted at several vents during past approximately 10,000 years. | None recognized. | None recognized. | None recognized. | Mafic cinder cones and lava flows of apparent
early Holocene age
(Miller, this report). |
Formation of cinder cones, small volumes of tephra, and lava flows; phreatic explosions. | |
| Salton Buttes rhyolite center
(16,000 years) (Muffler and White, 1969; Robinson and others, 1976) |
At least one silicic flow associated with rhyolite dome about 16,000 years ago. | Five silicic domes erupted from four vents about 16,000 years ago. | Probable small-volume pyroclastic eruptions associated with dome emplacement at several vents. | None recognized but may have occurred at several vents. | Products of subaqueous pyroclastic eruptions at least one vent. | None recognized. | Silicic pyroclastic and extrusive eruptions at
four vents about 16,000 K/Ar years ago
(Robinson and others, 1976). |
Explosive and extrusive rhyolitic eruptions; phreatic and phreatomagmatic eruptions. | |
| Ubehebe Crater area
(about 10,000 years) (Crowe and Fisher, 1973) |
None recognized. | None recognized. | Several mafic phreatomagmatic tephra eruptions in Holocene time. | None recognized. | Base-surge and phreatomagmatic tephra deposits associated with about 13 maar-crater eruptions. | None recognized. | Formation of maar craters and deposition of
phreatomagmatic tephra and base-surge deposits in early Holocene time
(Crowe and Fisher, 1973). |
Phreatomagmatic eruptions associated with base surges and small volumes of tephra. | |
| Golden Trout Creek volcanic field
(about 10,000 years) (Moore and Lanphere, 1983) |
One mafic cinder cone and lava flow about 10,000 to 5,000 years ago. | None recognized. | Mafic cinders erupted at one vent about 10,000 to 5,000 years ago. | None recognized. | None recognized. | None recognized. | Mafic cinder cone and lava flow about 10,000 t0
5,000 years ago
(Moore and Lanphere, 1983). |
Formation of cinder cones, small volumes of tephra and lava flows. | |
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