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> &g This is a multi-part message in MIME format. ------=_NextPart_000_00C5_01CF76CD.AD5EFB10 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Hi Randy & All, A picture helps. I remembered that I had a fairly large scale soil map of NS = (MacDougall & Nowland, 1972; 1:450,000) so dug it out. Your library = should have one if you don't. And a Google Earth image suggests that the = slacks are predominantly along the southerly third of Pomquet Beach and = parallel to the southerly shore of the beach. The soil to the west of the west esturary (Monk's Head and south), = and south west of the east esturary, is Queens; mostly unstructured, = poorly drained soil high in silt & clay. So the bottom muds of both = estuaries, except perhaps where exposed to wave action on sand, are = likely high in silt & clay and relatively impermeable.=20 That large nose of land between the two estuaries is Tormantine = (moderately coarse and medium textured well drained soil) as is Pomquet = Beach and land east of the east estuary. All of the Tormantine area is = nearly free of watercourses except for those that drain less permeable = soil to the south. So, as a rough estimate for this Tormentine costal = region, at least 60% of the annual ppt. is disposed of by deep = percolation and that flow has to go somewhere and exit at some lower = elevation. According to Google Earth some of that middle nose is about 85' = above sea level. [But it also had some of the estuary 8' above sea level = while much of the slacks area was 0' so precision is poor.]=20 Movement of water in soil is directly proportional to head, = hydraulic conductivity and cross-sectional area available for flow and = inversely proportional to flow length. If there is a sufficiently deep = layer of permeable bedrock under that nose and under the channel between = the nose and Pomquet Beach then much of the refill water could be from = the nose to the south.=20 I also wonder if the bottom of some of the slacks may have a lower = elevation than water in these estuaries when rivers are at full flow. = This would be flow driven by relatively small head but over a = relatively short flow path.=20 Yt, Dave Webster, Kentville =20 ----- Original Message -----=20 From: Randy Lauff=20 To: NatureNS=20 Sent: Friday, May 23, 2014 3:14 PM Subject: Re: [NatureNS] slacks - when do they refill? I have posted a picture of the slack here: = http://people.stfx.ca/rlauff/307/PomquetSlack.jpg. One person I asked = locally thought that the slack filled up again with the autumn rains. = That's probably right, but I still can't discount snow melt accompanied = by spring rain. I guess I'll find out this year. Randy _________________________________ RF Lauff Way in the boonies of Antigonish County, NS. On 21 May 2014 18:08, nancy dowd <nancypdowd@gmail.com> wrote: Maybe it is just evaporation. Water accumulates in the leaf-lined = slacks in the Spring (rain and melt) and eventually warming temps and = strong sun evaporate it until it is empty. Over the summer heat and sun = manage to keep up with the rainfall not allowing it to accumulate for = any length of time (it must be hot down in those slacks). Then once the = cooler temps and less intense sun of Fall take over rainwater can = accumulate once again in the slacks until it freezes. Just a guess. Nancy On 2014-05-21, at 4:39 PM, David & Alison Webster = <dwebster@glinx.com> wrote: > Hi Randy & All, > I had imagined these dunes to be bare sand. With tree cover on = the peaks and presumably none on the slacks there is another effect that = will increase effective ppt in the slacks; sublimation on the tree = canopy in calm weather and selective snow accumulation in treeless areas = (roads, glades, etc) in windy weather due to less turbulence and less = speed over glades.. > Yt, DW > ----- Original Message ----- > From: Randy Lauff > To: NatureNS > Sent: Wednesday, May 21, 2014 9:57 AM > Subject: Re: [NatureNS] slacks - when do they refill? > > Thanks folks, > > I haven't been there in winter, despite my being in NS now for = over 20 years. > > Here's the landscape picture though. Picture an accordion, partly = open lying on its back. The bellows represent the dune system at = Pomquet, there are peaks and troughs (slacks), and precious little other = elevations going on. At the slack in question, the surrounding peaks of = the dunes are dominated by white pine and oak, with other trees as well. > > Fred asked, if the dunes are sandy, how are they holding water in = the first place? Basically, I think there is leaf litter which may be = accumulating in the slack to slow the water seepage. Further to Anne's = email, the slack in question is well back from the salt water, I suspect = there is no salt to speak of in that water. Mosquitoes are there in the = billions, peepers are deafening, both suggesting fresh water (though I = realize a few mosquitoes can tolerate brackish water). > > Randy > > _________________________________ > RF Lauff > Way in the boonies of > Antigonish County, NS. > > > On 20 May 2014 18:24, David & Alison Webster<dwebster@glinx.com> = wrote: > Hi Randy & All, May 20, 2014 > I don't have a clear picture of the topography, either dune or = inland, but one possible source of water in the slacks is drifting of = snow into pools. > > In woods south of Kentville, where I used to walk in winter, = pools in woodland cradlehollows of swampy sites never froze. With 2'-3' = of snow on the ground, the air cone was typically about ~1' across at = snow level and 4" across at water level. Even at -20o C, with heavy = snowfall, 60 mph winds and drifting snow there would be no hint of ice. = From the viewpoint of ppt per unit area these cones act as black holes; = snow blows into them but, soon being water, can not escape. These air = cones were absent when snow was not deep enough to act as a good = insulator. With sufficient snow cover drifted ~level over the swamp, the = soil at the base of cradlehollows would warm sufficiently by ground heat = from below to melt overlying snow and eventually generate one of these = air cones. > > If these pools were sufficiently above the water table then = they would tend to be transient but, in most soils (given sufficient = iron and decomposable organic matter), infiltration rate at constant = head will gradually slow due to formation of a local iron pan over = decades or centuries. This effect interested me because ortstein is = sometimes very scattered; patches 3-4' wide and 10-15' apart and these = pools that collect below air cones could account for this. Also = prolonged wetting will slake any so