Editing Mount Baker (section)

====Historical activity====
[[File:Mount Baker steam plume from Bellingham, WA, 1999.jpg|thumb|right|Steam plume rising from Sherman Crater, December 1999, telephoto taken from Bellingham, Washington]]

Several eruptions occurred from Sherman Crater during the 19th century;<ref>{{cite book |last1=Tucker |first1=D.S |author-link1=Dave Tucker (geologist)|author-link2=Kevin M. Scott |last2=Scott |first2=K.M. |last3=Lewis |first3=D. R. |chapter=Field guide to Mount Baker volcanic deposits in the Baker River valley: Nineteenth Century lahars, tephras, debris avalanches, and early Holocene subaqueous lava |date=2007 |editor1-last=Stelling |editor1-first=P.L. |editor2-last=Tucker |editor2-first=D.S. |editor-link2=Dave Tucker (geologist)|title=Floods, Faults and Fire: Geological Fieldtrips in Washington State and Southwest British Columbia |series=Geol. Soc. Amer. Field Guide |volume=9 |page=83 |doi=10.1130/2007.fld009(04) |isbn=978-0-8137-0009-0 |chapter-url=https://books.google.com/books?id=F1Sx3i2CZyUC&pg=PA83 }}</ref> they were witnessed from the Bellingham area.<ref name="ScottTucker03">{{cite journal |last1=Scott |first1=K.M. |author-link=Kevin M. Scott |last2=Tucker |first2=D.S. |author-link2=Dave Tucker (geologist) |date=2003 |title=The Sherman Crater eruptive period at Mount Baker, North Cascades, 1843 To present: implications for reservoirs at the base of the volcano |url=http://www.mbvrc.wwu.edu/abstracts/abstractText.php?id=19 |journal=GSA Abstracts with Programs |volume=35 |issue=6 |access-date=2009-03-31 |archive-date=2011-07-20 |archive-url=https://web.archive.org/web/20110720122441/http://www.mbvrc.wwu.edu/abstracts/abstractText.php?id=19 |url-status=dead }}</ref> A possible eruption was seen in June 1792 during the Spanish expedition of [[Dionisio Alcalá Galiano]] and [[Cayetano Valdés y Flores|Cayetano Valdés]]. Their report read, in part:{{blockquote|During the night [while anchored in Bellingham Bay] we constantly saw light to the south and east of the mountain of Carmelo [Baker] and even at times some bursts of flame, signs which left no doubt that there are volcanoes with strong eruptions in those mountains.<ref>{{cite book |last=Kendrick |first=John |title=The Voyage of ''Sutil'' and ''Mexicana'', 1792: The last Spanish exploration of the Northwest Coast of America |date=1990 |publisher= The Arthur H. Clark Company |location=Spokane, Washington |isbn=0-87062-203-X |page=108}}</ref>}} Most of Mount Baker's eruptions that have a confirmed [[VEI]] level had a VEI of 2 but two possible eruptions had a VEI of 3.<ref>{{cite web|url=https://volcano.si.edu/volcano.cfm?vn=321010|title=Global Volcanism Program &#124; Baker|website=Smithsonian Institution &#124; Global Volcanism Program|access-date=2024-09-18}}</ref>

In 1843, explorers reported a widespread layer of newly fallen rock fragments "like a snowfall" and that the forest was "on fire for miles around". These fires were unlikely to have been caused by ashfall, however, as charred material is not found with deposits of this fine-grained [[volcanic ash]], which was almost certainly cooled in the atmosphere before falling. Rivers south of the volcano were reportedly clogged with ash, and Native Americans reported that many salmon perished. Reports of flooding on the Skagit River from the eruption are, however, probably greatly exaggerated.<ref>{{cite journal |last1=Scott |first1=K.M. |author-link1=Kevin M. Scott |last2=Tucker |first2=D.S. |author-link2=Dave Tucker (geologist) |date=2004 |title=Natural dams and floods of legend at Mount Baker volcano-evidence from the stratigraphic record of volcanic activity during the Sherman Crater eruptive period (AD 1843 to present) |journal=GSA Abstracts with Programs |volume=36 |issue=5 |page=377 |url=http://www.mbvo.wwu.edu/abstracts/abstractText.php?id=21 |access-date=2009-03-31 |archive-date=2010-07-02 |archive-url=https://web.archive.org/web/20100702042605/http://www.mbvo.wwu.edu/abstracts/abstractText.php?id=21 |url-status=dead }}</ref> A short time later, two collapses of the east side of Sherman Crater produced two lahars, the first and larger of which flowed into the natural Baker Lake, increasing its level by at least {{convert|10|ft|m}}. The location of the 19th-century lake is now covered by waters of the modern dam-impounded [[Baker Lake (Washington)|Baker Lake]]. Similar but lower-level hydrovolcanic activity at Sherman Crater continued intermittently for several decades afterward.<ref name="Topinka2"/><ref name=ScottTucker03/> On 26 November 1860, passengers who were traveling by steamer from [[New Westminster]] to Victoria reported that Mount Baker was "puffing out large volumes of smoke, which upon breaking, rolled down the snow-covered sides of the mountain, forming a pleasing effect of light and shade."<ref>{{cite book |url=https://archive.org/stream/historyofbritish00begguoft/historyofbritish00begguoft_djvu.txt |title=British Columbia: From the Earliest Times to the Present |first=Alexander |last=Begg |date=1894 |publisher=Toronto, Briggs |author-link=Alexander Begg (1825–1905) }}</ref> In 1891, about {{convert|15|km3|cumi|abbr=on}} of rock fell producing a lahar that traveled more than {{convert|6|mi|km|abbr=on}} and covered {{convert|1|sqmi|km2|adj=on|abbr=on}}.<ref>{{cite journal |last1=Lewis |first1=D.R. |last2=Scott |first2=K.M. |author-link2=Kevin M. Scott|last3=Tucker |first3=D.S. |author-link3=Dave Tucker (geologist)|date=2007 |title=Debris avalanches in Rainbow Creek at Mount Baker, Washington — dating and matrix analysis |journal=Geological Society of America Abstracts with Programs |volume=39 |issue=4 |page=66 |url=http://www.mbvrc.wwu.edu/abstracts/abstractText.php?id=37 |access-date=2009-03-31 |archive-date=2016-03-03 |archive-url=https://web.archive.org/web/20160303212404/http://www.mbvrc.wwu.edu/abstracts/abstractText.php?id=37 |url-status=dead }}retrieved 2009-03-31</ref>

Activity in the 20th century decreased from the 19th century. Numerous small debris avalanches fell from Sherman Peak and descended the Boulder Glacier; a large one occurred on July&nbsp;27, 2007.<ref>{{cite web |url=http://www.mbvrc.wwu.edu/images/images.shtml |title=Boulder Debris Avalanche |work=Mount Baker Volcano Research Center |access-date=2009-03-31 |archive-date=2009-10-18 |archive-url=https://web.archive.org/web/20091018144050/http://www.mbvrc.wwu.edu/images/images.shtml |url-status=dead }}</ref><ref>{{cite journal |last1=Frank |first1=D. |last2=Post |first2=A. |last3=Friedman |first3=J.D. |date=1975 |title=Recurrent geothermally induced debris avalanches on Boulder Glacier, Mount Baker, Washington |journal=Journal of Research, US Geological Survey |volume=3 |issue=1 |pages=77–87 |bibcode=1975JRUGS...3...77F }}</ref> [[File:Boulder Glacier 3737.JPG|right|thumb|Mount Baker and [[Boulder Glacier (Washington)|Boulder Glacier]] as seen from the southeast]] In early March 1975, a dramatic increase in fumarolic activity and snow melt in the Sherman Crater area raised concern that an eruption might be imminent.<ref name="Gardner"/> Heat flow increased more than tenfold.<ref name="Scott"/><ref name="Topinka2"/> Additional monitoring equipment was installed and several geophysical surveys were conducted to try to detect the movement of magma.<ref name="Gardner"/> The increased thermal activity prompted public officials and Puget Power to temporarily close public access to the popular Baker Lake recreation area and to lower the reservoir's water level by {{convert|10|m|ft|order=flip}}. If those actions had not been taken,{{Citation needed|date=April 2023}} significant avalanches of debris from the Sherman Crater area could have swept directly into the reservoir, triggering a disastrous wave that could have caused human fatalities and damage to the reservoir.<ref name=ScottTucker03/><ref name="Brantley99">{{cite web |last=Brantley |first=Steven R. |title=Volcanoes of the United States, Online Version 1.1 |work = USGS General Interest Publications |publisher=[[United States Geological Survey]] |date=1999-01-04 |url=http://pubs.usgs.gov/gip/volcus/ |access-date=2008-05-11 }}</ref> Other than the increased heat flow, few anomalies were recorded during the geophysical surveys, nor were any other precursory activities observed that would indicate that magma was moving up into the volcano.<ref name="Gardner"/> Several small lahars formed from material ejected onto the surrounding glaciers and acidic water was discharged into Baker Lake for many months.<ref name="Scott"/><ref name="Topinka2"/>

Activity gradually declined over the next two years, but stabilized at a higher level than before 1975.<ref name="Scott"/><ref name="Topinka2"/> The increased level of fumarolic activity has continued at Mount Baker since 1975, but no other changes suggest that magma movement is involved.<ref name="Gardner">{{cite book |last1=Gardner |first1=C.A. |url=http://vulcan.wr.usgs.gov/Volcanoes/Baker/Hazards/ |title=Potential Volcanic Hazards from Future Activity of Mount Baker, Washington: U.S. Geological Survey Open-File Report 95-498 |last2=Scott |first2=K.M. |last3=Miller |first3=C.D. |last4=Myers |first4=B. |last5=Hildreth |first5=W. |last6=Pringle |first6=P.T. |date=1995 |publisher=United States Geological Survey |author-link=Cynthia Gardner |author-link2=Kevin M. Scott |author-link5=Wes Hildreth |archive-date=October 6, 2012 |access-date=May 8, 2008 |archive-url=https://web.archive.org/web/20121006192252/http://vulcan.wr.usgs.gov/Volcanoes/Baker/Hazards/ |url-status=dead }}</ref>