EVIDENCE FROM GARIBALDI PROVINCIAL PARK, BRITISH COLUMBIA, FOR A COMPLEX HISTORY OF HOLOCENE GLACIER FLUCTUATIONS IN THE WESTERN CORDILLERA OF THE AMERICAS

The history of Holocene glacier fluctuations in Garibaldi Provincial Park, southwestern British Columbia, has been determined using dendrochronology, lichenometry, and radiocarbon dating of in situ and detrital wood. All major phases of glacier advance recognized elsewhere in the western Canadian Cordillera are represented in our record: the Little Ice Age, which most likely began in Garibaldi Park about AD 1050, culminated about AD 1700, and was followed by several readvances dating to the mid- and late nineteenth century; the Tiedemann Advance, which occurred between 3900 and 3000 years ago; and the Garibaldi Phase between 7300 and 5800 years ago. We also found evidence for glacier activity at the time of the 8200-year cooling event in the North Atlantic region and for an advance around 1500 years ago. The latter advance has recently been documented at several glaciers elsewhere in the Coast Mountains and Canadian Rocky Mountains. Several glaciers in Garibaldi Park also advanced about 4500 years ago. The record from Garibaldi Park appears to be the most complete obtained to date from the western Cordillera of the Americas. The times of glacier advance in Garibaldi Park are broadly synchronous with those known from the Patagonian Andes. The synchronous behavior of glaciers in the two hemispheres during the Holocene suggests that the same or similar climate forcing mechanisms operated on a global scale. However, extents of the various advances are different in the two regions. Little Ice Age advances of most Northern Hemisphere glaciers were the most extensive advances of the Holocene. In contrast, the Little Ice Age advances of many land-based glaciers in the Patagonian Andes were less extensive than some earlier Holocene advances. The causes of these differences remain unknown.