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Cleft Segment

Photo of this volcano
  • Country
  • Volcanic Region
  • Landform | Volc Type
  • Last Known Eruption
  • 44.83°N
  • 130.3°W

  • -2,140 m
    -7,021 ft

  • 331030
  • Latitude
  • Longitude

  • Summit
    Elevation

  • Volcano
    Number


Most Recent Bulletin Report: September 1987 (Ref 1989)

New lava mounds along ridge

[Comparison of September 1987 SeaBeam data with a single 1983 SeaBeam pass and a more detailed 1981 survey revealed a series of new lava mounds along a segment of the Juan de Fuca Ridge from about 45.01°N to 45.15°N, 130.15°W (figure 1). No seismic data are available and no eruption time(s) can be definitively established. However, large hydrothermal "megaplumes" that may have occurred during the same rifting episode were detected by research vessels in mid-August 1986 and mid-September 1987 (Baker and others, 1989).]

Figure (see Caption) Figure 1. SeaBeam bathymetric map of the southern Juan de Fuca Ridge (uncorrected for sound velocity), from Embley and others, 1991. Contour interval, 100 m. Temperature anomaly contours (°C) of megaplumes I (August 1986) and II (September 1987) are from Baker and others, 1989. Pillow mounds are shown in black, the zone of young sheet-flows is indicated by diagonal shading, and high-temperature vents are marked by stars.

References. Baker, E.T., Lavelle, J.W., Feely, R.A., Massoth, G.J., and Walker, S.L., 1989, Episodic venting of hydrothermal fluids from the Juan de Fuca Ridge: JGR, v. 94, p. 9237-9250.

Embley, R.W., Chadwick, W., Perfit, M.R., and Baker, E.T., 1991, Geology of the Northern Cleft Segment, Juan de Fuca Ridge: recent lava flows, sea-floor spreading, and the formation of megaplumes: Geology, v. 19, p. 771-775.

Information Contacts: See References.

The Global Volcanism Program has no Weekly Reports available for Cleft Segment.

Bulletin Reports - Index

Reports are organized chronologically and indexed below by Month/Year (Publication Volume:Number), and include a one-line summary. Click on the index link or scroll down to read the reports.

09/1987 (Ref 1989) New lava mounds along ridge




Information is preliminary and subject to change. All times are local (unless otherwise noted)


September 1987 (Ref 1989)

New lava mounds along ridge

[Comparison of September 1987 SeaBeam data with a single 1983 SeaBeam pass and a more detailed 1981 survey revealed a series of new lava mounds along a segment of the Juan de Fuca Ridge from about 45.01°N to 45.15°N, 130.15°W (figure 1). No seismic data are available and no eruption time(s) can be definitively established. However, large hydrothermal "megaplumes" that may have occurred during the same rifting episode were detected by research vessels in mid-August 1986 and mid-September 1987 (Baker and others, 1989).]

Figure (see Caption) Figure 1. SeaBeam bathymetric map of the southern Juan de Fuca Ridge (uncorrected for sound velocity), from Embley and others, 1991. Contour interval, 100 m. Temperature anomaly contours (°C) of megaplumes I (August 1986) and II (September 1987) are from Baker and others, 1989. Pillow mounds are shown in black, the zone of young sheet-flows is indicated by diagonal shading, and high-temperature vents are marked by stars.

References. Baker, E.T., Lavelle, J.W., Feely, R.A., Massoth, G.J., and Walker, S.L., 1989, Episodic venting of hydrothermal fluids from the Juan de Fuca Ridge: JGR, v. 94, p. 9237-9250.

Embley, R.W., Chadwick, W., Perfit, M.R., and Baker, E.T., 1991, Geology of the Northern Cleft Segment, Juan de Fuca Ridge: recent lava flows, sea-floor spreading, and the formation of megaplumes: Geology, v. 19, p. 771-775.

Information Contacts: See References.

This compilation of synonyms and subsidiary features may not be comprehensive. Features are organized into four major categories: Cones, Craters, Domes, and Thermal Features. Synonyms of features appear indented below the primary name. In some cases additional feature type, elevation, or location details are provided.

Eruptive History

There is data available for 3 confirmed Holocene eruptive periods.

1986 Aug 16 (?) ± 15 days Confirmed Eruption VEI: 0

Episode 1 | Eruption N Cleft Segment, S Juan de Fuca Ridge
1986 Aug 16 (?) ± 15 days - Unknown Evidence from Observations: Reported

List of 2 Events for Episode 1 at N Cleft Segment, S Juan de Fuca Ridge

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Lava flow
1986 Aug
(?)
   - - - - VEI (Explosivity Index)

1982 Jul 2 (in or before) ± 182 days Confirmed Eruption VEI: 0

Episode 1 | Eruption N Cleft Segment, S Juan de Fuca Ridge
1982 Jul 2 (in or before) ± 182 days - Unknown Evidence from Observations: Reported

List of 2 Events for Episode 1 at N Cleft Segment, S Juan de Fuca Ridge

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Lava flow
1982
(in or before)
   - - - - VEI (Explosivity Index)

0270 BCE (?) Confirmed Eruption VEI: 0

Episode 1 | Eruption S Cleft Segment, S Juan de Fuca Ridge
0270 BCE (?) - Unknown Evidence from Isotopic: Uranium-series

List of 2 Events for Episode 1 at S Cleft Segment, S Juan de Fuca Ridge

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Lava flow
0270 BCE
(?)
   - - - - VEI (Explosivity Index)
Deformation History

There is no Deformation History data available for Cleft Segment.

Emission History

There is no Emissions History data available for Cleft Segment.

GVP Map Holdings

The Global Volcanism Program has no maps available for Cleft Segment.

Smithsonian Sample Collections Database

There are no samples for Cleft Segment in the Smithsonian's NMNH Department of Mineral Sciences Rock and Ore collection.

External Sites