Stratigraphic evidence for multiple Holocene advances of Lillooet Glacier, southern Coast Mountains, British Columbia

2004 ◽  
Vol 41 (8) ◽  
pp. 903-918 ◽  
Author(s):  
Alberto V Reyes ◽  
John J Clague
Keyword(s):  
British Columbia ◽  
Little Ice Age ◽  
Late Holocene ◽  
Woody Debris ◽  
Ice Age ◽  
Lateral Moraine ◽  
Southern Coast ◽  
Cross Sectional ◽  
Coast Mountains ◽  
Paleoecological Reconstructions

Holocene lateral moraines in the Coast Mountains of British Columbia are commonly composed of multiple drift units related to several glacier advances. In this paper, we document lateral moraine stratigraphy at Lillooet Glacier in the southern Coast Mountains. Five tills, separated by laterally extensive paleosols and layers of large woody debris, were found in three cross-sectional exposures through the northeast lateral moraine and two shallow gullies incised into its steep proximal face. Eighteen new radiocarbon ages constrain the timing of five separate advances of Lillooet Glacier: (1) prior to 3000 14C years BP; (2) ~3000 14C years BP; (3) ~2500 14C years BP; (4) ~1700 to 1400 14C years BP; and (5) during the Little Ice Age (LIA), after 470 14C years BP. The Lillooet Glacier chronology is broadly synchronous with other glacier records from the Coast Mountains. These records collectively demonstrate climate variability at higher frequencies during the late Holocene than is apparent from many paleoecological reconstructions. Reconstructions of glacier fluctuations are often hampered by poor preservation of landforms that predate the extensive LIA advances of the latest Holocene. Our results highlight the potential of lateral moraine stratigraphy for reconstructing these earlier events.

Late Holocene vegetation and climate change at Moraine Bog, Tiedemann Glacier, southern Coast Mountains, British Columbia

2007 ◽  
Vol 44 (5) ◽  
pp. 707-719 ◽  
Author(s):  
T A Arsenault ◽  
John J Clague ◽  
R W Mathewes
Keyword(s):  
Climate Change ◽  
British Columbia ◽  
Late Holocene ◽  
Water Levels ◽  
Ice Age ◽  
Silty Clay ◽  
Lateral Moraine ◽  
Southern Coast ◽  
Coast Mountains ◽  
Vegetation And Climate

Moraine Bog lies just outside the outermost lateral moraine of Tiedemann Glacier in the southern Coast Mountains of British Columbia. A sediment core taken from the wetland was analyzed for pollen, magnetic susceptibility, and loss on ignition to reconstruct changes in vegetation and climate during the late Holocene. Vegetation changed little between about 3500 and 2400 14C years BP. A period of local disturbance marked by deposition of a silty clay bed and increases in Alnus pollen, likely reflecting cooler moister conditions, coincides with an extensive Holocene advance of Tiedemann Glacier about 2400 14C years BP. Warm dry conditions between about 1900 and 1500 14C years BP are suggested by peak values of Pseudotsuga pollen and increasing Nuphar sclereids; the latter suggests lowered water levels. This period coincides with a time of drought and increased fire frequency in the southernmost Coast Mountains. About 1300 14C years BP, the forest became more coastal in composition with abundant Tsuga heterophylla and Abies. An increase in Tsuga mertensiana pollen suggests the onset of cool and wet conditions by ca. 500 14C years BP, coincident with the Little Ice Age. The record of inferred climate change at Moraine Bog is broadly synchronous with other paleoclimate records from the Coast Mountains and, at the centennial scale, with records elsewhere in the world.

Late Holocene glacial activity of Bridge Glacier, British Columbia Coast Mountains

2007 ◽  
Vol 44 (12) ◽  
pp. 1753-1773 ◽  
Author(s):  
Sandra M Allen ◽  
Dan J Smith
Keyword(s):  
British Columbia ◽  
Little Ice Age ◽  
Late Holocene ◽  
Ice Age ◽  
Significant Advance ◽  
Lateral Moraine ◽  
Coast Mountains ◽  
The Pacific ◽  
First Millennium ◽  
Subfossil Wood

Bridge Glacier is a prominent eastward-flowing valley glacier located on the east side of the Pacific Ranges within the southern British Columbia Coast Mountains. The terminus of Bridge Glacier has retreated at rates up to 125 m/year over the last 50 years and currently calves into proglacial Bridge Lake. Field investigations of the recently deglaciated terrain and moraines led to the discovery of detrital boles and glacially sheared stumps. Dendroglaciological analyses of this subfossil wood produced five radiocarbon-controlled floating tree-ring chronologies. The relative age and stratigraphic location of these samples revealed that Bridge Glacier experienced at least four periods of significant advance during the late Holocene: a Tiedemann-aged advance ca. 3000 14C years BP, an unattributed advance ca. 1900 14C years BP, a first millennium advance ca. 1500 14C years BP, and a Little Ice Age advance beginning ca. 700 14C years BP. Lichenometric investigations at eight terminal and lateral moraine complexes identified early Little Ice Age moraine stabilization during the late 13th to early 14th centuries, with subsequent ice-front oscillations ending in the middle 15th, early 16th, middle to late 17th, early 18th, middle to late 19th, and early 20th centuries. These investigations build upon previous research and compliment recent geobotanical evidence emerging from other glaciers in this region that describe multiple late Holocene glacier advances. The discovery of a glacially sheared whitebark pine stump dating to 1500 ± 50 14C years BP provides irrevocable proof for an advance of Bridge Glacier during a time when glaciers throughout Pacific North America were also expanding.

Dendroglaciological investigations of mid- to late-Holocene glacial activity in the Mt. Waddington area, British Columbia Coast Mountains, Canada

The Holocene ◽  
2012 ◽  
Vol 23 (1) ◽  
pp. 93-103 ◽  
Author(s):  
Bethany Coulthard ◽  
Dan J Smith ◽  
Terri Lacourse
Keyword(s):  
British Columbia ◽  
Little Ice Age ◽  
Late Holocene ◽  
Ice Age ◽  
Lateral Moraine ◽  
Valley Bottom ◽  
Glacier Surface ◽  
Coast Mountains ◽  
Field Investigations ◽  
Subfossil Wood

Dendroglaciological investigations near Mt. Waddington in the central British Columbia Coast Mountains provide an enhanced perspective of Holocene glacial activity. Field investigations at Confederation, Franklin, and Jambeau glaciers led to the discovery of subfossil wood mats encased in glacial deposits and glacially sheared stumps buried beneath till. Radiocarbon-dated wood collected from valley-bottom and lateral moraine sites at Confederation Glacier suggest that an early-Holocene advance occurred at c. 5665 cal. yr BP, followed by succeeding intervals of glacier expansion at c. 3700 and 3500 cal. yr BP. At Jambeau Glacier detrital wood mats buried close to the contemporary lateral moraine crests document glacier expansion at c. 3000 cal. yr BP. Detrital subfossil wood buried in lateral moraines at the confluence of Confederation and Franklin glaciers records distinct episodes of ‘Little Ice Age’ glacier expansion as early as c. 1212 cal. yr ad, and suggests the glacier surface continued to thicken until at least c. 1330–1410 cal. yr ad. An interval of downwasting and retreat followed, before late ‘Little Ice Age’ advances such as those at Jambeau Glacier were overwhelming valley-bottom forests by c. 1740 cal. yr ad. With the exception of the previously unrecognized advance of Confederation Glacier at c. 3700 cal. yr BP, our dendroglaciological findings corroborate the emerging record of Holocene glacier activity in the British Columbia Coast Mountains.

Glacier fluctuations during the past millennium in Garibaldi Provincial Park, southern Coast Mountains, British Columbia

2007 ◽  
Vol 44 (9) ◽  
pp. 1215-1233 ◽  
Author(s):  
Johannes Koch ◽  
John J Clague ◽  
Gerald D Osborn
Keyword(s):  
British Columbia ◽  
Little Ice Age ◽  
Ice Age ◽  
Southern Coast ◽  
Coast Mountains ◽  
The Past ◽  
Glacier Fluctuations ◽  
Garibaldi Provincial Park ◽  
Provincial Park ◽  
Past Millennium

The Little Ice Age glacier history in Garibaldi Provincial Park (southern Coast Mountains, British Columbia) was reconstructed using geomorphic mapping, radiocarbon ages on fossil wood in glacier forefields, dendrochronology, and lichenometry. The Little Ice Age began in the 11th century. Glaciers reached their first maximum of the past millennium in the 12th century. They were only slightly more extensive than today in the 13th century, but advanced at least twice in the 14th and 15th centuries to near their maximum Little Ice Age positions. Glaciers probably fluctuated around these advanced positions from the 15th century to the beginning of the 18th century. They achieved their greatest extent between A.D. 1690 and 1720. Moraines were deposited at positions beyond present-day ice limits throughout the 19th and early 20th centuries. Glacier fluctuations appear to be synchronous throughout Garibaldi Park. This chronology agrees well with similar records from other mountain ranges and with reconstructed Northern Hemisphere temperature series, indicating global forcing of glacier fluctuations in the past millennium. It also corresponds with sunspot minima, indicating that solar irradiance plays an important role in late Holocene climate change.

Tree-ring derived Little Ice Age temperature trends from the central British Columbia Coast Mountains, Canada

2012 ◽  
Vol 78 (3) ◽  
pp. 417-426 ◽  
Author(s):  
Kara J. Pitman ◽  
Dan J. Smith
Keyword(s):  
British Columbia ◽  
Coarse Woody Debris ◽  
Little Ice Age ◽  
Woody Debris ◽  
High Elevation ◽  
Ice Age ◽  
Climatic Fluctuations ◽  
Coast Mountains ◽  
Air Temperature Anomaly ◽  
June July

AbstractMost glaciers in the British Columbia Coast Mountains reached their maximum Holocene extent during the Little Ice Age. Early- and late-Little Ice Age intervals of expansion and retreat fluctuations describe a mass-balance response to changing climates. Although existing dendroclimatic records provide insights into these climatic fluctuations over the last 400 yr, their short durations prohibit evaluation of early-Little Ice Age climate variability. To extend the duration of these records, submerged coarse woody debris salvaged from a high-elevation lake was cross-dated to living chronologies. The resulting chronology provides the opportunity to reconstruct a regional June–July air-temperature anomaly record extending from AD 1225 to 2010. The reconstruction shows that the intervals AD 1350–1420, 1475–1550, 1625–1700 and 1830–1940 characterized distinct periods of below-average June–July temperature followed by periods of above-average temperature. Our reconstruction provides the first annually resolved insights into high-elevation climates spanning the Little Ice Age in this region and indicates that Little Ice Age moraine stabilization corresponds to persistent intervals of warmer-than-average temperatures. We conclude that coarse woody debris submerged in high-elevation lakes has considerable potential for developing lengthy proxy climate records, and we recommend that researchers focus attention on this largely ignored paleoclimatic archive.

Late Holocene glacial activity in Manatee Valley, southern Coast Mountains, British Columbia, Canada

2011 ◽  
Vol 48 (3) ◽  
pp. 603-618 ◽  
Author(s):  
Lindsey Koehler ◽  
Dan J. Smith
Keyword(s):  
British Columbia ◽  
Late Holocene ◽  
18Th Century ◽  
Ice Age ◽  
Coast Mountains ◽  
Mountain Glaciers ◽  
Subsequent Episode ◽  
Glacial Expansion ◽  
Insight Into ◽  
Lichen Growth

The dendroglaciologic and lichenometric research methodologies employed in this study provide a perspective of glaciological conditions from 5 ka to present in a remote headwater area of the British Columbia Coast Mountains. Since Holocene ice fronts of four glaciers at this site periodically extended below treeline, previous glacier advances overrode and buried forests beneath till deposits. This study suggests that glaciers were expanding into standing forests at 4.76 and 3.78 ka. Following glacier expansion at 3.78 ka, a period of recession ensued when glaciers withdrew upvalley long enough for the development of deep pedogenic surfaces and the growth of trees exceeding 300 years. Investigations at Beluga and Manatee glaciers benchmark a subsequent episode of significant glacial expansion at 2.42 ka referred to as the “Manatee Advance”. This advance has regional correlatives and is distinguished from the Tiedemann Advance at Manatee Glacier by documentation of substantive ice front retreat between the two episodes. Examination of Little Ice Age (LIA) deposits in the study area allowed for presentation and application of a revised Rhizocarpon spp. lichen growth curve. Lichenometric surveys of lateral moraines associated with Beluga, Manatee, and Oluk glaciers provided limited insight into their early LIA behaviour but record advances during the 15th and 16th centuries. Locally, glaciers achieved their maximum LIA size prior to an early to mid 18th century moraine-building event. This reconstruction of Holocene glacial history offers insights consistent with the emerging record of glacier activity described for other southern British Columbia Coast Mountain glaciers.

Little Ice Age glacial activity in the Mt. Waddington area, British Columbia Coast Mountains, Canada

2003 ◽  
Vol 40 (10) ◽  
pp. 1413-1436 ◽  
Author(s):  
S J Larocque ◽  
D J Smith
Keyword(s):  
British Columbia ◽  
Little Ice Age ◽  
Ice Age ◽  
Climate Forcing ◽  
Medium Size ◽  
Coast Mountains ◽  
Mountain Ranges ◽  
Relative Age ◽  
History Of ◽  
Forcing Mechanisms

The establishment of fourteen Little Ice Age (LIA) glacier chronologies in the Mt. Waddington area led to the development of an extended history of glacial activity in this portion of the southern British Columbia Coast Mountains, Canada. The glaciers were located within four different mountain ranges, and were of varying size and aspect. Dendrochronological and lichenometric techniques were used to provide relative age estimates of moraines formed as glacier termini retreated from advanced positions. Evidence for pre-LIA glacial events is best preserved at Tiedemann Glacier, where the oldest glacial advances date to A.D. 620 and 925–933. Soil-covered and well-vegetated moraines built at Cathedral, Pagoda, and Siva glaciers date to between A.D. 1203 and 1226. Following this event, moraines constructed at Ragnarok, Siva, and Cathedral glaciers in the mid-14th century suggest glaciers in the region underwent a period of downwasting and retreat before readvancing. The majority of moraines recorded in the Mt. Waddington area describe late-LIA glacial events shown to have constructed moraines that date to A.D. 1443–1458, 1506–1524, 1562–1575, 1597–1621, 1657–1660, 1767–1784, 1821–1837, 1871–1900, 1915–1928, and 1942–1946. Over the last 500 years, these moraine-building episodes were shown to occur on average every 65 years and suggest there has been prolonged synchronicity in the glaciological response to persistent climate-forcing mechanisms. Nevertheless, our analysis suggests that local factors, such as aspect and size, play an important role in individual glacial response. Notably, ice termini of medium-size glaciers facing eastwards showed a quicker response to climatically induced mass balance changes.

Late Holocene glacial history of Scimitar Glacier, Mt. Waddington area, British Columbia Coast Mountains, Canada

2013 ◽  
Vol 50 (12) ◽  
pp. 1195-1208 ◽  
Author(s):  
Jessica A. Craig ◽  
Dan J. Smith
Keyword(s):  
British Columbia ◽  
Late Holocene ◽  
Regional Climate ◽  
Ice Age ◽  
Climate Trends ◽  
Glacier Surface ◽  
Coast Mountains ◽  
Standing Trees ◽  
History Of ◽  
Glacial Expansion

Scimitar Glacier originates below the northeast face of Mt. Waddington in the southern British Columbia Coast Mountains and flows 18 km down valley to calve into a proglacial lake. At several locations, downwasting of the glacier surface has exposed stacked till units separated by wood-bearing horizons in the proximal slopes of lateral moraines flanking the glacier. Historical moraine collapse and erosional breaching has also revealed the remains of standing trees buried in moraine-dammed lake sediments. Radiocarbon and tree-ring dating show that Scimitar Glacier expanded down valley at least three times in the late Holocene. The earliest evidence found for ice expansion indicates Scimitar Glacier was advancing in 3167–2737 cal years BP in association with the regional Tiedemann Advance. Following this advance, the glacier downwasted prior to expanding in 1568–1412 cal years BP during the First Millennial Advance. A final period phase of moraine construction was initiated during late Little Ice Age glacial expansion before A.D. 1742 and extended until at least A.D. 1851, after which Scimitar Glacier began to recede and downwaste. This record is comparable to that recorded at other glaciers in the southern British Columbia Coast Mountains and confirms the long-term relationship between regional climate trends and glacier behaviour in this setting.

Did rock avalanche deposits modulate the late Holocene advance of Tiedemann Glacier, southern Coast Mountains, British Columbia, Canada?

2013 ◽  
Vol 384 ◽  
pp. 154-164 ◽  
Author(s):  
Brian Menounos ◽  
John J. Clague ◽  
Garry K.C. Clarke ◽  
Shaun A. Marcott ◽  
Gerald Osborn ◽  
...  
Keyword(s):  
British Columbia ◽  
Late Holocene ◽  
Rock Avalanche ◽  
Southern Coast ◽  
Coast Mountains
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