Reconstructing late Holocene relative sea-level changes at the Magdalen Islands (Gulf of St. Lawrence, Canada) using multi-proxy analyses

Proxy records of late Holocene relative sea-level changes are important for our understanding of mechanisms that drive contemporary sea-level trends. In the Gulf of Saint Lawrence (eastern Canada), the Magdalen Islands currently experience higher than global average rates of relative sea-level rise. This article presents original reconstruction data of sea-level changes from the Magdalen Islands over the past few millennia collected from a variety of coastal deposits and proxy records including salt-marsh foraminifera, testate amoebae and plant macrofossils. Reconstructed late Holocene relative sea-level trends are between 1.3 and 2.0mm a(-1) for the past 2000 years. When combined with contemporaneous trends in tide-gauge data from Cap-aux-Meules (Magdalen Islands), multi-proxy data show acceleration in the rate of relative sea-level rise to over 4mm a(-1) during the 20th century. This signal corresponds to similar inflexions also registered in salt marshes and tide-gauge data along the east coast of North America. Copyright (C) 2017 John Wiley & Sons, Ltd.