{{Short description|Active transform fault in Canada and Alaska}} [[File:Alaska earthquakes.jpg|thumb|400px|Tectonic map of Alaska and northwestern Canada showing main faults and historic earthquakes]]The '''Queen Charlotte Fault''' is an active [[transform fault]] on the boundary between the [[North American plate|North American]] plate and [[Pacific plate|Pacific plates]].<ref>{{Cite journal|last1=Trehu|first1=A. M.|last2=Scheidhauer|first2=M.|last3=Rohr|first3=K. M. M.|last4=Tikoff|first4=B.|last5=Walton|first5=M. A. L.|last6=Gulick|first6=S. P. S.|last7=Roland|first7=E. C.|date=2015-03-03|title=An Abrupt Transition in the Mechanical Response of the Upper Crust to Transpression along the Queen Charlotte Fault|journal=Bulletin of the Seismological Society of America|volume=105|issue=2B|pages=1114–1128|doi=10.1785/0120140159|bibcode=2015BuSSA.105.1114T |hdl=2152/43270 |s2cid=128679814 |issn=0037-1106|hdl-access=free}}</ref><ref name=":13">{{Cite journal|last1=Walton|first1=M. A. L.|last2=Gulick|first2=S. P. S.|last3=Haeussler|first3=P. J.|last4=Roland|first4=E. C.|last5=Trehu|first5=A. M.|date=2015-04-14|title=Basement and Regional Structure Along Strike of the Queen Charlotte Fault in the Context of Modern and Historical Earthquake Ruptures|journal=Bulletin of the Seismological Society of America|volume=105|issue=2B|pages=1090–1105|doi=10.1785/0120140174|bibcode=2015BuSSA.105.1090W |hdl=2152/43271 |s2cid=59376353 |issn=0037-1106|hdl-access=free}}</ref> It is [[Canada]]'s right-lateral [[strike-slip]] equivalent to the [[San Andreas Fault]] to the south in [[California]].<ref name=":22">{{Cite journal|last1=Rohr|first1=K. M. M.|last2=Tryon|first2=A. J.|date=2010|title=Pacific-North America plate boundary reorganization in response to a change in relative plate motion: Offshore Canada|journal=Geochemistry, Geophysics, Geosystems|language=en|volume=11|issue=6|doi=10.1029/2009GC003019|s2cid=129230105 |issn=1525-2027|doi-access=free|bibcode=2010GGG....11.6007R }}</ref> The Queen Charlotte Fault forms a [[triple junction]] at its southern with the [[Cascadia subduction zone]] and the [[Explorer Ridge]] (the [[Queen Charlotte triple junction]]). The Queen Charlotte Fault (QCF) forms a [[transpression]]al plate boundary, and is as active as other major transform fault systems (such as [[San Andreas Fault|San Andreas]] or [[Alpine Fault|Alpine]]) in terms of slip rates and seismogenic potential.<ref name=":3">{{Cite journal|last1=Yue|first1=Han|last2=Lay|first2=Thorne|last3=Freymueller|first3=Jeffrey T.|last4=Ding|first4=Kaihua|last5=Rivera|first5=Luis|last6=Ruppert|first6=Natalia A.|last7=Koper|first7=Keith D.|date=November 2013|title=Supershear rupture of the 5 January 2013 Craig, Alaska ( M w 7.5) earthquake: 2013 CRAIG EARTHQUAKE SUPERSHEAR RUPTURE|url=http://doi.wiley.com/10.1002/2013JB010594|journal=Journal of Geophysical Research: Solid Earth|language=en|volume=118|issue=11|pages=5903–5919|doi=10.1002/2013JB010594|s2cid=3754158 }}</ref> It sustains the highest-known [[Deformation (physics)|deformation]] rates among [[Continental plate|continental]] or [[Continent-ocean boundary|continent-ocean]] [[Transform fault|transform]] systems globally, accommodating more than 50 mm/yr of [[Dextral fault|dextral]] offset.<ref name=":43">{{Cite journal|last1=Brink|first1=U. S. ten|last2=Miller|first2=N. C.|last3=Andrews|first3=B. D.|last4=Brothers|first4=D. S.|last5=Haeussler|first5=P. J.|date=2018|title=Deformation of the Pacific/North America Plate Boundary at Queen Charlotte Fault: The Possible Role of Rheology|url=https://onlinelibrary.wiley.com/doi/abs/10.1002/2017JB014770|journal=Journal of Geophysical Research: Solid Earth|language=en|volume=123|issue=5|pages=4223–4242|doi=10.1002/2017JB014770|bibcode=2018JGRB..123.4223T |hdl=1912/10462 |s2cid=133742253 |issn=2169-9356|hdl-access=free}}</ref> The entire {{Convert|900|km|adj=mid}} offshore length has ruptured in seven magnitude 7+ events during the last century, making the cumulative historical [[seismic moment]] release higher than any other modern transform plate boundary system.<ref>Bostwick, T. (1984). A re-examination of the August 22, 1949 Queen Charlotte earthquake.</ref>
The fault is named for the Queen Charlotte Islands (now [[Haida Gwaii]]), which lie just north of the triple junction. The Queen Charlotte Fault continues northward along the [[Alaska]]n coast, where it is called the '''Fairweather Fault'''.<ref>{{Cite journal|last1=Brothers|first1=Daniel S.|last2=Miller|first2=Nathaniel C.|last3=Barrie|first3=J. Vaughn|last4=Haeussler|first4=Peter J.|last5=Greene|first5=H. Gary|last6=Andrews|first6=Brian D.|last7=Zielke|first7=Olaf|last8=Watt|first8=Janet|last9=Dartnell|first9=Peter|date=2020-01-15|title=Plate boundary localization, slip-rates and rupture segmentation of the Queen Charlotte Fault based on submarine tectonic geomorphology|journal=Earth and Planetary Science Letters|language=en|volume=530|article-number=115882|doi=10.1016/j.epsl.2019.115882|s2cid=210615976 |issn=0012-821X|doi-access=free|bibcode=2020E&PSL.53015882B |hdl=10754/660310|hdl-access=free}}</ref> The two segments are collectively called the '''Queen Charlotte-Fairweather Fault System'''.
== Fault orientation and plate motion == The junction of the Queen Charlotte, Fairweather, and Transition faults is located at the southeastern tip of the [[Yakutat Block|Yakutat block]], an oceanic plateau and microplate.<ref name=":02">{{Cite journal|last1=Trehu|first1=A. M.|last2=Scheidhauer|first2=M.|last3=Rohr|first3=K. M. M.|last4=Tikoff|first4=B.|last5=Walton|first5=M. A. L.|last6=Gulick|first6=S. P. S.|last7=Roland|first7=E. C.|date=2015-05-01|title=An Abrupt Transition in the Mechanical Response of the Upper Crust to Transpression along the Queen Charlotte Fault|url=https://pubs.geoscienceworld.org/bssa/article/105/2B/1114-1128/331755|journal=Bulletin of the Seismological Society of America|language=en|volume=105|issue=2B|pages=1114–1128|doi=10.1785/0120140159|bibcode=2015BuSSA.105.1114T |hdl=2152/43270 |s2cid=128679814 |issn=0037-1106|hdl-access=free}}</ref> The southern boundary of the QCF is marked by the complex Pacific–North American–Explorer [[triple junction]] off the coast of southern [[British Columbia]].<ref name=":02"/> The Queen Charlotte Fault continues northward along the [[Alaska]]n coast, where it is called the Fairweather Fault. The two segments are collectively called the Queen Charlotte-Fairweather Fault System. The current state of [[Transpression|transpressive]] plate boundary systems results from spatial and temporal changes between both [[Rheology|rheologic]] and [[Kinematics|kinematic]] parameters. From north to south, there is a decreasing rate of [[Convergent boundary|convergence]]<ref name=":02"/> and change in fault obliquity which appears to divide the fault into at least three distinct kinematic zones<ref name=":13"/> along [[strike and dip|strike]] with associated changes in seafloor morphology, fault structure, and [[seismicity]].<ref name=":22"/> The northern, central, and southern segments with maximum obliquity (approximately 15°–20°) occur south of 53.2°N, and minimum obliquity (less than 5°) occurs north of 56°N. Existing [[Geophysical survey|geophysical]] data suggest abrupt transitions in deformation mechanisms and plate boundary dynamics across these boundaries with incipient [[Thrust fault|underthrusting]] and [[strain partitioning]] in the south along Haida Gwaii,<ref>{{Cite journal|last1=Barrie|first1=J. Vaughn|last2=Conway|first2=Kim W.|last3=Harris|first3=Peter T.|date=2013-08-01|title=The Queen Charlotte Fault, British Columbia: seafloor anatomy of a transform fault and its influence on sediment processes|journal=Geo-Marine Letters|language=en|volume=33|issue=4|pages=311–318|doi=10.1007/s00367-013-0333-3|bibcode=2013GML....33..311B |s2cid=128409033 |issn=1432-1157}}</ref> distributed transpression in the central segment,<ref name=":02"/> and highly localized strike-slip deformation in the north.<ref name=":43"/> There are various mechanisms proposed to accommodate oblique convergence along the QCF, including underthrusting, strain partitioning,<ref name=":13"/> crustal thickening,<ref>{{Cite journal|last1=Hyndman|first1=R. D.|last2=Hamilton|first2=T. S.|date=1993-08-10|title=Queen Charlotte Area Cenozoic tectonics and volcanism and their association with relative plate motions along the northeastern Pacific Margin|url=http://doi.wiley.com/10.1029/93JB00777|journal=Journal of Geophysical Research: Solid Earth|language=en|volume=98|issue=B8|pages=14257–14277|doi=10.1029/93JB00777|bibcode=1993JGR....9814257H |url-access=subscription}}</ref> and distributed shear.<ref name=":22" /><ref name=":02"/> Through geologic time, a change in Pacific plate motion beginning as recently as approximately 6 [[Megaannus|Ma]]<ref>{{Cite journal|last1=Doubrovine|first1=Pavel V.|last2=Tarduno|first2=John A.|date=2008|title=Linking the Late Cretaceous to Paleogene Pacific plate and the Atlantic bordering continents using plate circuits and paleomagnetic data|journal=Journal of Geophysical Research: Solid Earth|language=en|volume=113|issue=B7|doi=10.1029/2008JB005584|issn=2156-2202|doi-access=free|bibcode=2008JGRB..113.7104D }}</ref> or as early as approximately 12 Ma<ref>{{Cite journal|last1=DeMets|first1=C|last2=Merkouriev|first2=S|date=2016-11-01|title=High-resolution reconstructions of Pacific–North America plate motion: 20 Ma to present|journal=Geophysical Journal International|volume=207|issue=2|pages=741–773|doi=10.1093/gji/ggw305|doi-access=free|issn=0956-540X}}</ref> caused an increase in convergence along the entire length of the fault and initiated underthrusting<ref>{{Cite journal|last1=Bustin|first1=A. M. M.|last2=Hyndman|first2=R. D.|last3=Kao|first3=H.|last4=Cassidy|first4=J. F.|date=2007-12-01|title=Evidence for underthrusting beneath the Queen Charlotte Margin, British Columbia, from teleseismic receiver function analysis|journal=Geophysical Journal International|volume=171|issue=3|pages=1198–1211|doi=10.1111/j.1365-246X.2007.03583.x|issn=0956-540X|doi-access=free|bibcode=2007GeoJI.171.1198B }}</ref> along the southern segment where convergence is highest,<ref name=":13"/> a process that ultimately led to the 2012 Haida Gwaii thrust earthquake.<ref>{{Citation|last1=Bird|first1=Alison L.|title=The October 2012 magnitude (Mw) 7.8 earthquake offshore Haida Gwaii, Canada|date=2016-02-01|url=https://zenodo.org/record/999242|journal=Bulletin of the International Seismological Centre |volume=49 |issue=7–12|pages=41–72|place=Thatcham, UK|publisher=International Seismological Centre|doi=10.5281/zenodo.999242|access-date=2021-11-24|last2=Cassidy|first2=John F.|last3=Kao|first3=Honn|last4=Leonard|first4=Lucinda J.|last5=Allen|first5=Trevor I.|last6=Nykolaishen|first6=Lisa|last7=Dragert|first7=Herb|last8=Hobbs|first8=Tiegan E.|last9=Farahbod|first9=Amir M.|s2cid=199107488 }}</ref>
== Crustal deformation along strike ==
=== Southern segment === [[Crustal deformation]] via [[strain partitioning]] likely dominates the southern segment,<ref>{{Cite journal|last1=Hyndman|first1=R. D.|last2=Rogers|first2=G. C.|date=1981|title=Seismicity surveys with ocean bottom seismographs off western Canada|url=http://doi.wiley.com/10.1029/JB086iB05p03867|journal=Journal of Geophysical Research|language=en|volume=86|issue=B5|page=3867|doi=10.1029/JB086iB05p03867|bibcode=1981JGR....86.3867H |issn=0148-0227|url-access=subscription}}</ref><ref>{{cite journal | doi=10.1139/e89-218 | title=A microseismicity study of the Queen Charlotte Islands region | date=1989 | last1=Bérubé | first1=Joane | last2=Rogers | first2=Garry C. | last3=Ellis | first3=Robert M. | last4=Hasselgren | first4=Elizabeth O. | journal=Canadian Journal of Earth Sciences | volume=26 | issue=12 | pages=2556–2566 | bibcode=1989CaJES..26.2556B }}</ref><ref name=":02"/> as evidenced by the [[Thrust fault|thrust]] mechanism of the [[2012 Haida Gwaii earthquake]],<ref>{{Cite journal|last1=Lay|first1=Thorne|last2=Ye|first2=Lingling|last3=Kanamori|first3=Hiroo|last4=Yamazaki|first4=Yoshiki|last5=Cheung|first5=Kwok Fai|last6=Kwong|first6=Kevin|last7=Koper|first7=Keith D.|date=2013-08-01|title=The October 28, 2012 Mw 7.8 Haida Gwaii underthrusting earthquake and tsunami: Slip partitioning along the Queen Charlotte Fault transpressional plate boundary|url=https://www.sciencedirect.com/science/article/pii/S0012821X13002434|journal=Earth and Planetary Science Letters|language=en|volume=375|pages=57–70|doi=10.1016/j.epsl.2013.05.005|issn=0012-821X}}</ref> where geoscientists observed downwarping and [[normal fault]]ing on the [[Pacific plate]] west of [[Haida Gwaii]].<ref>{{Cite journal|last=Rohr|first=K. M. M.|date=2015-04-14|title=Plate Boundary Adjustments of the Southernmost Queen Charlotte Fault|journal=Bulletin of the Seismological Society of America|volume=105|issue=2B|pages=1076–1089|doi=10.1785/0120140162|bibcode=2015BuSSA.105.1076R |issn=0037-1106}}</ref> This hypothesis is also supported by the [[Geomorphology|morphology]] of the Queen Charlotte Terrace, a {{Convert|30|km|4=-wide|adj=mid}} deformed [[accretionary prism|accretionary-prism]]-like complex west of the main QCF trace.<ref>{{Cite journal|last1=Riedel|first1=M.|last2=Yelisetti|first2=S.|last3=Papenberg|first3=C.|last4=Rohr|first4=K.M.M.|last5=Côté|first5=M.M.|last6=Spence|first6=G.D.|last7=Hyndman|first7=R.D.|last8=James|first8=T.|date=2020-12-23|title=Seismic velocity structure of the Queen Charlotte terrace off western Canada in the region of the 2012 Haida Gwaii Mw 7.8 thrust earthquake|journal=Geosphere|volume=17|issue=1|pages=23–38|doi=10.1130/GES02258.1|issn=1553-040X|doi-access=free}}</ref> Several recent{{When|date=March 2025}} studies based on [[seismicity]], [[Global Positioning System|GPS]] observations of coseismic and postseismic deformation, and [[Geothermal gradient|thermal modeling]] support the presence of a shallow plate boundary thrust.<ref>{{Cite journal |last1=Wang |first1=K. |last2=He |first2=J. |last3=Schulzeck |first3=F. |last4=Hyndman |first4=R. D. |last5=Riedel |first5=M. |date=2015-04-07 |title=Thermal Condition of the 27 October 2012 Mw 7.8 Haida Gwaii Subduction Earthquake at the Obliquely Convergent Queen Charlotte Margin |journal=Bulletin of the Seismological Society of America |volume=105 |issue=2B |pages=1290–1300 |doi=10.1785/0120140183 |bibcode=2015BuSSA.105.1290W |issn=0037-1106}}</ref><ref>{{Cite journal|last1=Farahbod|first1=A. M.|last2=Kao|first2=H.|date=2015-04-07|title=Spatiotemporal Distribution of Events during the First Week of the 2012 Haida Gwaii Aftershock Sequence|journal=Bulletin of the Seismological Society of America|volume=105|issue=2B|pages=1231–1240|doi=10.1785/0120140173|bibcode=2015BuSSA.105.1231F |issn=0037-1106}}</ref><ref>{{Cite journal|last1=Kao|first1=H.|last2=Shan|first2=S.-J.|last3=Farahbod|first3=A. M.|date=2015-04-07|title=Source Characteristics of the 2012 Haida Gwaii Earthquake Sequence|journal=Bulletin of the Seismological Society of America|volume=105|issue=2B|pages=1206–1218|doi=10.1785/0120140165|bibcode=2015BuSSA.105.1206K |issn=0037-1106}}</ref><ref>{{Cite journal|last1=Nykolaishen|first1=L.|last2=Dragert|first2=H.|last3=Wang|first3=K.|last4=James|first4=T. S.|last5=Schmidt|first5=M.|date=2015-04-07|title=GPS Observations of Crustal Deformation Associated with the 2012 Mw 7.8 Haida Gwaii Earthquake|journal=Bulletin of the Seismological Society of America|volume=105|issue=2B|pages=1241–1252|doi=10.1785/0120140177|bibcode=2015BuSSA.105.1241N |issn=0037-1106}}</ref>
=== Central segment === In the central segment, abrupt changes in both seafloor morphology and structural geometry accompany a decrease in convergence angle. The Queen Charlotte Terrace widens and deepens, forming a series of oblique [[ridge]]s and [[Sedimentary basin|basins]] west of the QCF main trace.<ref>{{Cite journal|last1=Rohr|first1=Kristin M. M.|last2=Scheidhauer|first2=Maren|last3=Trehu|first3=Anne M.|date=2000-04-10|title=Transpression between two warm mafic plates: The Queen Charlotte Fault revisited|journal=Journal of Geophysical Research: Solid Earth|language=en|volume=105|issue=B4|pages=8147–8172|doi=10.1029/1999JB900403|doi-access=free|bibcode=2000JGR...105.8147R }}</ref><ref name=":02" /> There is a distinct structural transition due to a change in the stress regime from [[pure shear]] in the southern QCF segment to [[simple shear]] in the central QCF segment as a result of convergence decreasing below a critical angle of approximately 15°.<ref name=":02" />
=== Northern segment === In the northern segment, which bore the [[epicenter]] of the [[Strike-slip tectonics|strike-slip]] [[2013 Craig, Alaska earthquake|2013 Craig earthquake]], [[Bathymetry|bathymetric]] data suggests that the ridge-basin complex gives way to simpler fault morphology.<ref name=":43"/> Deformation largely occurs on what appears to be a single strike-slip structure.<ref name=":43" /> The same location also marks [[earthquake rupture]] boundaries between the 2013 Craig event<ref name=":32">{{Cite journal|last1=Yue|first1=Han|last2=Lay|first2=Thorne|last3=Freymueller|first3=Jeffrey T.|last4=Ding|first4=Kaihua|last5=Rivera|first5=Luis|last6=Ruppert|first6=Natalia A.|last7=Koper|first7=Keith D.|date=November 2013|title=Supershear rupture of the 5 January 2013 Craig, Alaska ( M w 7.5) earthquake: 2013 CRAIG EARTHQUAKE SUPERSHEAR RUPTURE|url=http://doi.wiley.com/10.1002/2013JB010594|journal=Journal of Geophysical Research: Solid Earth|language=en|volume=118|issue=11|pages=5903–5919|doi=10.1002/2013JB010594|s2cid=3754158 }}</ref> and the 1972 M7.6 [[Sitka, Alaska|Sitka]] event,<ref>{{Cite journal|last1=Schell|first1=Melissa M.|last2=Ruff|first2=Larry J.|date=1989-04-15|title=Rupture of a seismic gap in southeastern Alaska: the 1972 Sitka earthquake (Ms 7.6)|journal=Physics of the Earth and Planetary Interiors|language=en|volume=54|issue=3|pages=241–257|doi=10.1016/0031-9201(89)90246-X|hdl=2027.42/27965 |issn=0031-9201|hdl-access=free}}</ref><ref>{{Cite book|last1=Plafker|first1=George|last2=Moore|first2=J. Casey|last3=Winkler|first3=Gary R.|title=The Geology of Alaska |date=1994-01-01|chapter=Geology of the southern Alaska margin|pages=389–449 |chapter-url=https://pubs.geoscienceworld.org/gsa/books/book/875/chapter/4867303/Geology-of-the-southern-Alaska-margin|language=en|doi=10.1130/DNAG-GNA-G1.389|isbn=0-8137-5219-1 }}</ref> as well as the inferred intersection of the [[Chatham Strait]] Fault and the Aja [[Fracture zone|Fracture Zone]] (FZ) with the Queen Charlotte Fault; the Aja FZ also marks a 3-million-year contrast in Pacific plate crustal age.<ref name=":13"/> Accommodation of strike-slip plate motion along a narrow deformation zone is consistent with [[focal mechanism]]s determined for the Craig event and its [[aftershock]]s.<ref>{{Cite journal|last1=Holtkamp|first1=S.|last2=Ruppert|first2=N.|date=2015-04-07|title=A High Resolution Aftershock Catalog of the Magnitude 7.5 Craig, Alaska, Earthquake on 5 January 2013|journal=Bulletin of the Seismological Society of America|volume=105|issue=2B|pages=1143–1152|doi=10.1785/0120140179|bibcode=2015BuSSA.105.1143H |issn=0037-1106}}</ref> Combined with other observations along the fault, this behavior implies that there may be a critical angle of obliquity within the simple shear regime at which distributed shear across multiple structures is not sustainable, and deformation can be more easily accommodated on a single structure. The fault has been the source of large, very large, and great [[earthquakes]].
==Significant earthquakes along the fault== {| border="2" cellpadding="2" cellspacing="0" style="margin: 1; border: 1px #aaaaaa solid; border-collapse: collapse; float: right; font-size: 90%; text-align: center;" !style="background: #f9f9f9;"| Date !style="background: #f7f9f7;"| [[Moment magnitude scale|''M'']] !style="background: #f9f9f9;"| Damage !style="background: #f7f9f7;"| Article |- | 1929 | ~7 | | |- | 1949 | 8.1 | Landslides, housing and infrastructure damage, [[oil tank]] collapse | [[1949 Queen Charlotte Islands earthquake]] |- | 1958 | 7.8 | Landslide, megatsunami (524 m), housing and infrastructure destruction, 5 casualties | [[1958 Lituya Bay earthquake and megatsunami]] |- | 1970 | 7.4 | Landslides | |- | 1990 | 5.3 | Minor | |- | 2001 | 6.3 | Minor | |- | 2004 | 6.8 | Land slippage | |- | 2008 | 6.5 | Minor | |- | 2009 | 6.6 | Minor | |- | 2012 | 7.8 | Temporary desiccation of [[Gwaii Haanas National Park Reserve and Haida Heritage Site|hot springs]], 1 casualty (indirect) | [[2012 Haida Gwaii earthquake]] |- | 2013 | 7.6 | Minor | [[2013 Craig, Alaska earthquake]] |- | 2014 | 6.0 | [[Submarine communications cable|Undersea fiber-optic cable]] damage, causing widespread telecommunications outages | [[2014 Palma Bay earthquake]] |- | 2025 | 7.0 | Minor; Some landslides | |- |} Six large earthquakes have occurred along the Queen Charlotte Fault within the last hundred years: a [[Richter magnitude scale|magnitude]] 7 event in 1929, a [[1949 Queen Charlotte earthquake|magnitude 8.1 in 1949]] (Canada's largest recorded earthquake since the [[1700 Cascadia earthquake]]), a [[1958 Lituya Bay earthquake and megatsunami|magnitude 7.8 in 1958]], a magnitude 7.4 in 1970, a [[2012 Haida Gwaii earthquake|magnitude 7.8 in 2012]], and a [[2013 Craig, Alaska earthquake|magnitude 7.6 in 2013]].<ref name=":3" />
The [[P wave|P nodal]] [[focal mechanism]] for the [[1949 Queen Charlotte Islands earthquake|1949 earthquake]] indicates a virtually pure [[Strike-slip tectonics|strike-slip]] movement with a northwest-striking nodal plane corresponding to the [[Strike (geology)|strike]] of the fault.<ref name=":3" /> This is similar to the 1970 earthquake, which also showed a strike-slip movement with a small but significant [[Thrust tectonics|thrust]] component, consistent with relative plate motion. The 1949 earthquake was larger than the [[1906 San Francisco earthquake]], causing a nearly {{Convert|500|km|4=-long|adj=mid}} segment of the Queen Charlotte Fault to break.
The [[1958 Lituya Bay earthquake and megatsunami|1958 earthquake]] had a magnitude of 7.8 and led to a major [[landslide]] in [[Lituya Bay]], Alaska. This resulted in a {{Convert|1720|ft|m|abbr=off|adj=on}} tsunami that crashed into a mountainside, the largest tsunami run-up ever recorded.<ref>{{Cite web|title=Earthquake Hazards in Southeastern Alaska|url=https://www.usgs.gov/centers/pcmsc/science/earthquake-hazards-southeastern-alaska?qt-science_center_objects=0#qt-science_center_objects|access-date=2021-03-07|publisher=United States Geological Survey|language=en}}</ref>
The [[2012 Haida Gwaii earthquake|2012 magnitude 7.8 earthquake]] struck off the western coast of [[Haida Gwaii]] at around 8:10pm Pacific Time on Saturday, 27 October. This was the biggest quake in Canadian territory since 1949. Aftershocks as large as magnitude 6.3 were reported. A {{Convert|45|cm|adj=mid}} tsunami was reported locally. Alerts were sent across the Pacific Basin.<ref>CBC Newsworld, "7.7 Magnitude Quake Breaking News Special", airdate: 27–28 October 2012</ref> This earthquake did not have any major impacts, except for the temporary desiccation of the hot springs on [[Hotspring Island]]. The springs seemed to have returned to borderline-normal functioning as of July 2014.<ref>[http://www.cbc.ca/daybreaknorth/interviews/2014/06/06/haida-gwaiis-hotsprings-island-showing-signs-of-recovery/ Haida Gwaii's Hotsprings Island showing signs of recovery]</ref>
The 2012 quake was remarkable for having been a [[Thrust fault|thrust]], rather than [[Strike slip fault|strike-slip]], tremor, more like the mechanism of the [[Cascadia subduction zone]] to the south.<ref>{{Cite web|url=https://www.earthmagazine.org/article/superquakes-supercycles-and-global-earthquake-clustering-recent-research-and-recent-quakes|first1=Chris |last1=Goldfinger |first2=Yasutaka |last2=Ikeda |first3=Robert S. |last3=Yeats|title=Superquakes, supercycles, and global earthquake clustering: Recent research and recent quakes reveal surprises in major fault systems|date=December 3, 2012|website=EARTH Magazine}}</ref> Recent{{When|date=March 2025}} detailed seafloor mapping has revealed the expression of the Queen Charlotte Fault on the seafloor,<ref>{{cite journal | doi=10.1007/s00367-013-0333-3 | title=The Queen Charlotte Fault, British Columbia: Seafloor anatomy of a transform fault and its influence on sediment processes | date=2013 | last1=Barrie | first1=J. Vaughn | last2=Conway | first2=Kim W. | last3=Harris | first3=Peter T. | journal=Geo-Marine Letters | volume=33 | issue=4 | pages=311–318 | bibcode=2013GML....33..311B }}</ref> including the truncation of [[submarine canyon]]s that occur along the [[continental slope]].<ref>{{cite journal | doi=10.1016/j.dsr2.2013.06.017 | title=Hanging canyons of Haida Gwaii, British Columbia, Canada: Fault-control on submarine canyon geomorphology along active continental margins | date=2014 | last1=Harris | first1=Peter T. | last2=Barrie | first2=J. Vaughn | last3=Conway | first3=Kim W. | last4=Greene | first4=H. Gary | journal=Deep Sea Research Part II: Topical Studies in Oceanography | volume=104 | pages=83–92 | bibcode=2014DSRII.104...83H }}</ref>
==See also== *[[List of earthquakes in Canada]] *[[Queen Charlotte Sound (Canada)|Queen Charlotte Sound]] *[[Ring of Fire]]
==References== {{reflist}}
==External links== * [http://www.aeic.alaska.edu/maps/QueenCharlotteFairweather_fault.html Queen Charlotte-Fairweather Fault System – Alaska Earthquake Information Center] {{Webarchive|url=https://web.archive.org/web/20090108045436/http://www.aeic.alaska.edu/maps/QueenCharlotteFairweather_fault.html |date=2009-01-08 }}
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[[Category:Seismic faults of Canada]] [[Category:Seismic zones of British Columbia]] [[Category:Geology of the Pacific Ocean]] [[Category:Coast of British Columbia]] [[Category:Strike-slip faults]] [[Category:Supershear earthquakes]] [[Category:Oceanography of Canada]]