GEOSCAN, résultats de la recherche


TitreExtending the Place Glacier mass-balance record to AD 1585, using tree rings and wood density
AuteurWood, L J; Smith, D J; Demuth, M N
SourceQuaternary Research (New York) vol. 76, no. 3, 2011 p. 305-313,
Séries alt.Secteur des sciences de la Terre, Contribution externe 20090438
Documentpublication en série
Mediapapier; en ligne; numérique
Lat/Long OENS-122.6167 -122.6000 50.4333 50.4167
Sujetsvégétation; dendrochronologie; climatologie; climat; effets climatiques; glaciers; levés glaciaires; géologie des dépôts meubles/géomorphologie; géochronologie
Illustrationslocation maps; tables; graphs; plots
ProgrammeLes sciences de la Terre à l'appui de la caractérisation, à l'échelle nationale, des impacts des changements climatiques sur la masse continentale canadienne, Géosciences de changements climatiques
Résumé(disponible en anglais seulement)
Recognizing that climate influences both annual tree-ring growth and glacier mass balance, changes in the mass balance of Place Glacier, British Columbia, were documented from increment core records. Annually resolved ring-width (RW), maximum (MXD), and mean density (MD) chronologies were developed from Engelmann spruce and Douglas-fir trees sampled at sites within the surrounding region. A snowpack record dating to AD 1730 was reconstructed using a multivariate regression of spruce MD and fir RW chronologies. Spruce MXD and RW chronologies were used to reconstruct winter mass balance (Bw) for Place Glacier to AD 1585. Summer mass balance (Bs) was reconstructed using the RW chronology from spruce, and net balance was calculated from Bw and Bs. The reconstructions provide insight into the changes that snowpack and mass balance have undergone in the last 400 years, as well as identifying relationships to air temperature and circulation indices in southern British Columbia. These changes are consistent with other regional mass-balance reconstructions and indicate that the persistent weather systems characterizing large scale climate-forcing mechanisms play a significant glaciological role in this region. A comparison to dated moraine surfaces in the surrounding region substantiates that the mass-balance shifts recorded in the proxy data are evident in the response of glaciers throughout the region.