Keptekiwiku’s: To freeze or not to freeze
In the Bras d'or Lake Biosphere Reserve
It will soon be November in the Bras d’or Lake Biosphere and in the Mi’kmaw calendar that is ‘Rivers starting to freeze time’ (Keptekiwiku’s). As I think back over past autumns, I wonder whether the rivers will actually start to freeze in November, and how that may change with our changing climate. Shall we think about re-naming Keptekiwiku’s? Let’s examine this proposal.
The calendar on my wall, computer and cell phone is called the Gregorian calendar after Pope Gregory XIII who introduced it in 1582. It is a solar calendar based on a 365-day year divided into 12 months of irregular lengths with an extra day added nearly every 4 years. Many great minds came up with that plan, but it took a pope to implement it! Although we attempt to track Mi’kmaw months alongside Gregorian calendar months, they are not really equivalent. There are actually 13 moon cycles in the traditional Mi’kmaw calendar every year. Each cycle starts with the new moon and is named after a significant environmental occurrence at that time. A lunar month is equivalent to the time that the moon takes to pass through each of its phases (new moon, half moon and full moon) and return back to its original position - this takes approximately 29.5 days. A lunar year therefore has approximately 354 days. The Gregorian calendar is based on a solar year which has about 365 days. This leaves an 11-day difference between one solar year and one lunar year and at least part of a thirteenth month. This year, the November moon is Nov 6 to Dec 6. Does that time period seem more likely for ‘rivers starting to freeze’?
Ice-up conditions at two Environment Canada stream gauging stations reported over the last ten to twelve years may provide insight into freezing patterns in the Biosphere. Ice formation in the Middle River can start as early as December 4, as was measured in 2007 and November 29 in the River Denys as noted that same year. However, timing of ice formation depends upon the hydrology of the river (water velocities and the inflow of warmer ground water). In Glen Brook, near Melford, temperatures measured during some November days showed a huge range, from 1.7 to 10 degrees between 2001 and 2015. So, rivers may start to freeze during Keptekiwiku’s, but it is probably a bit of shell ice in the shallows, and it is dependent on time, location and geology in the Bras d’or Lake Biosphere.
The Bras d’or Lake Biosphere is in the centre of Unama’ki, one of the seven traditional districts of Mi’kma’ki. The original seven districts extend from the Gaspe region of Quebec to the northern part of Maine. Present day conditions for ‘rivers starting to freeze’ are clearly more probable near the northern parts of Mi’kma’ki. For example, air temperatures monitored by Environment Canada at the South Tetagouche station near Bathurst, New Brunswick, yielded much lower ‘climate normal’ temperatures than Baddeck during November for the years 1981 to 2010. Although I don’t have water temperatures from that area, those air temperatures say to me that rivers starting to freeze is a very likely scenario during the November moon in South Tetagouche. Ice-up in the Petacodiac River near Moncton, in the middle of Mi’kma’ki supports that conclusion. In a technical report by D. Caissie in 2000 (Canadian Technical Report of Fisheries and Aquatic Sciences 2301) it was shown that ice-up occurred before November 11 on average 77% of the time between 1962 and 1996. It seems likely that the November moon may have earned its’ name in one of the other districts of Mi’kma’ki.
With a changing climate and warming oceans, the time gap between the November moon and Keptekiwiku’s, or rivers starting to freeze time, is likely to widen. As we are surrounded by water, our climate is strongly influenced by oceanic processes. This end of the province is influenced by the northerly flowing Labrador current whereas the southern end feels the influence of the warm Gulf Stream. So, if we look closely at the scientific modelling relating global climate change to the Labrador current, the picture is clear. We are in for a warmer ocean and warmer Novembers in the future with the gap between the November moon and ‘rivers starting to freeze’ ever-widening!
Dr. Annamarie Hatcher is a consulting ecologist and a board member of the Bras d’or Lake Biosphere Reserve Association. Thanks are due to Lynn and Fred Baechler who are always ready to share data! For more information about the Bras d’or Lake Biosphere Reserve Association, please visit http://blbra.ca/.
Major currents of the Northeast Atlantic. Warm currents are colored with reds and colder currents with blues. Map courtesy of Gulf of Maine’ Census of Marine Life (COML) - www.gulfofmaine-census.org.
Data courtesy of Environment and Climate Change Canada (canada.ca)