{{Short description|Mountain in California, United States}} {{Infobox mountain | name = Mount Hannah | image = | image_size = | image_upright = | image_alt = | image_caption = <!-- MAP CODE TBA --> <!----------------------- HIGHEST POINT --> | highest = | highest_location = | elevation = {{convert|3978|ft}} | prominence = {{convert|1338|ft}} | parent_peak = | isolation = {{convert|7.94|km}} | isolation_parent = Cobb Mountain | listing = | coordinates = {{coord|38.887258 |-122.746296|display=it}} | map = USA California | map_caption = Location in California

<!----------------------- DIMENSIONS --> | length = | length_km = | length_mi = | length_orientation = | length_ref = | width = | width_km = | width_mi = | width_orientation = | width_ref = | area = | area_km2 = | area_mi2 = | area_ref = | volume = | volume_km3 = | volume_mi3 = | volume_ref = <!----------------------- NAMING --> | etymology = | nickname = | native_name = | native_name_lang = | translation = | pronunciation = | authority = <!----------------------- GEOGRAPHY --> | country = United States | country_type = | state = California | state_type = State | location = | district = Lake County | district_type = County | range_coordinates = | range_coordinates_ref = | range = | borders_on = | biome = <!----------------------- GEOLOGY --> | formed_by = | orogeny = | age = | type = Lava dome<ref>{{cite web|url=https://volcano.si.edu/volcano.cfm?vn=323100|title=Global Volcanism Program &#124; Clear Lake Volcanic Field|website=Smithsonian Institution &#124; Global Volcanism Program|access-date=2024-09-11}}</ref> | geology = | volcanic_zone = Clear Lake volcanic field | last_eruption = }} '''Mount Hannah''' is a mountain in the Mayacamas Mountains of the Northern California Coast Ranges. It is in Lake County, California.

==Location==

Mount Hannah is in Lake County, California.{{sfn|Kirmse}} It is one of the mountains in the Cobb Mountain Area, many of which have volcanic origin. Others are Cobb Mountain, the most dominant, Seigler Mountain and Boggs Mountain. There are isolated small valleys and basins between the mountain peaks.{{sfn|Lake County Planning Department|1989|p=3.1}}

Mount Hannah has an elevation of {{convert|3692|ft}}. Clean prominence is {{convert|1338|ft}}. Isolation is {{convert|7.94|km}}. The nearest higher neighbor is Cobb Mountain to the south.{{sfn|Kirmse}}

==Geology==

Mount Hannah formed quite quickly during a polarity transition.{{sfn|Iyer|Oppenheimer|Hitchcock|Roloff|1980|p=73}} It was built up by a number of closely-spaced eruptions.{{sfn|Iyer|Oppenheimer|Hitchcock|Roloff|1980|p=72}} Three of the dacites in the Mount Hannah sequence have been dated to between 0.90 and 0.92 million years ago.{{sfn|Iyer|Oppenheimer|Hitchcock|Roloff|1980|p=73}} There are indications that there may be a crustal magma chamber about {{convert|10|-|15|km}} in diameter and a depth of {{convert|15|km}} below Mount Hannah, with a temperature above {{convert|550|C}}.{{sfn|Iyer|Oppenheimer|Hitchcock|Roloff|1980|p=107}}

==Notes== {{notes}}{{reflist|25em}}

==Sources== {{refbegin}} *{{citation |publisher=U.S. Government Printing Office|chapter=Large Teleseismic P-Wave Delays in the Geysers-Clear Lake Geothermal Area |last1=Iyer|first1=H.M.|last2=Oppenheimer|first2=David H|last3=Hitchcock|first3=Tim|first4=Jeffrey N. |last4=Roloff |first5=John M. |last5=Coakley |title=U.S. Geological Survey Professional Paper|chapter-url=https://books.google.com/books?id=nobUxSwJySAC&pg=RA2-PA54|year=1980}} *{{citation |url=https://www.peakbagger.com/peak.aspx?pid=55256 |accessdate=2021-04-28 |first= Andrew |last=Kirmse |title=Mount Hannah, California |work=Peakbagger }} *{{citation |url=https://www.lakecountyca.gov/Assets/Departments/CDD/Area+Plans/Cobb+Mountain+Area+Plan.pdf |accessdate=2021-04-29 |author=Lake County Planning Department |title=Cobb Mountain Area Plan |type=Preliminary Draft |date=May 1989}} {{refend}} {{Mayacamas Mountains}} {{authority control}}

{{DEFAULTSORT:Hannah, Mount}} Category:Mountains of Lake County, California Category:Mayacamas Mountains Category:Pleistocene lava domes Category:Volcanoes of California Category:Lava domes of the United States Category:Pleistocene California