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The following talk and excursion might be of interest to list members in =
the western valley region. Sorry for the short notice.
Jon Percy
Granville Ferry, NS
----- Original Message -----=20
From: Jon Percy=20
To: jon-percy@ns.sympatico.ca=20
Sent: Wednesday, September 30, 2009 9:26 AM
Subject: AFNS - Geology and Sea Level Change Field Trip.
Hi AFNSers and Friends;
The following includes more details about the Geology and Sea Level =
Change Field Trip planned for this Saturday October 3rd. We will meet =
half hour earlier than originally planned - it is now 9:30 a.m. at the =
End of the Line Pub in Bridgetown. Also, Tim suggests we bring bag =
lunches as he expects to finish by about 3 p.m. If you are interested in =
participating it is important that you let Gini (638-8353 or =
gproulx@eastlink.ca ) or I (532-5129 or jon-percy@ns.sympatico.ca ) =
know as soon as possible and by Friday afternoon at the latest. The trip =
may be cancelled if there is insufficient interest. This is open to all, =
so please forward this to anyone you think may be interested.
Cheers
Jon
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
North Mountain Field Trip: Examples of the different volcanic flow units =
and evidence of past higher sea-levels and possible future sea-level =
rise impacts
=20
Tim Webster, PhD
Applied Geomatics Research Group
COGS, Middleton
timothy.webster@nscc.ca
825 5475
=20
The North Mountain is comprised of three volcanic flow units and was =
erupted from fissure volcanoes during the Triassic period, 200 Million =
Years ago. The three volcanic flow units are quite distinct and have =
variable resistance to erosion. As a result the morphology (shape) of =
the North Mountain reflects these differences in erodability of the flow =
units. The lower flow unit (oldest) is exposed along the south face of =
the North M Mountain and is quite thick, massive with columnar joints =
and very resistant to erosion. The resistance to erosion of this unit is =
in part why we have such a steep slope on the north side. The lower flow =
unit is overlaid by the Middle Flow unit which is comprised of several =
thin volcanic flows that are highly vesicular (gas bubbles). These air =
bubbles have been subsequently in filled with zeolite minerals as a =
result of ground water circulation through the rocks. Stilbite, Nova =
Scotia=92s mineral, is one such mineral that infill=92s these voids in =
the rocks. Zeolites have a unique crystal structure and grow radially =
outward. The Middle Flow unit is less resistant to erosion and is often =
referred to as =93rotten rock=94 by local construction operators. The =
Upper Flow unit overlies the Middle Flow Units and is similar to the =
lower flow unit in that it is resistant to erosion and often outcrops =
along the Bay of Fundy Coast.
=20
The flow units have been mapped with the aid of a new remote sensing =
technique known as LiDAR, Light Detection & Ranging. We use a laser =
onboard an aircraft to precisely measure the earth=92s topography (lay =
of the land) to an accuracy of 15 cm in the vertical. The measurements =
are then used to construct a continuous surface known as a Digital =
Elevation Model (DEM). We then use these DEM in the computer to better =
visualize the subtle topographic changes of the land surface. As a =
result we can see the contacts between the flow units and other =
interesting landforms including raised terraces along the Bay of Fundy =
that represent higher sea-levels. After deglaciation 12-15,000 years =
ago, the sea-level rose faster than the earth=92s crust rebounded. =
Evident of this high sea level is found at several locations along the =
coast in the form of terraces. Recent tide gauge records from Saint =
John, NB indicate relative sea-level is rising by 22 cm per century. =
This is a combination of crustal subsidence and global sea-level rise. =
We have also used these new LiDAR elevation models to map the town of =
Annapolis Royal and project possible flood limits based on storm surges =
and future projections of higher sea-levels. The Groundhog Day storm of =
1976 was used a bench mark storm and the flood extent was mapped using =
the LiDAR DEM. Future sea-level rise projections were then used with =
this storm to predict what areas are at risk if the storm were to =
reoccur in the future.
=20
The field trip will begin with a presentation of the sea-level history =
of the area, followed by an explanation of LiDAR and the improvements to =
topographic mapping that it provides. Flood maps of Annapolis Royal =
during the Groundhog Day storm and possible future flooding considering =
sea-level rise will be shown. Maps of the North Mountain will be =
displayed and the contact between the flow units identified. In addition =
we will examine these raised beach terraces that have resulted from past =
higher sea-levels. We will then depart to visit the different volcanic =
flow units and contacts in the field and the raised terraces along the =
coast.
Tim Webster, Ph.D.
Research Scientist, Applied Geomatics Research Group (AGRG)
Centre of Geographic Sciences (COGS), Nova Scotia Community College
=20
Chair, Halifax Branch, Canadian Institute of Geomatics
Adjunct professor, Acadia University, Dept. of Earth and Environmental =
Sciences
Adjunct professor, Dalhousie University, Dept. of Earth Sciences
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<DIV><FONT size=3D2 face=3DArial>The following talk and excursion might =
be of=20
interest to list members in the western valley region. Sorry for the =
short=20
notice.</FONT></DIV>
<DIV><FONT size=3D2 face=3DArial></FONT> </DIV>
<DIV><FONT size=3D2 face=3DArial>Jon Percy</FONT></DIV>
<DIV><FONT size=3D2 face=3DArial>Granville Ferry, NS</FONT></DIV>
<DIV><FONT size=3D2 face=3DArial></FONT> </DIV>
<DIV style=3D"FONT: 10pt arial">----- Original Message -----=20
<DIV style=3D"BACKGROUND: #e4e4e4; font-color: black"><B>From:</B> <A=20
title=3Djon-percy@ns.sympatico.ca =
href=3D"mailto:jon-percy@ns.sympatico.ca">Jon=20
Percy</A> </DIV>
<DIV><B>To:</B> <A title=3Djon-percy@ns.sympatico.ca=20
href=3D"mailto:jon-percy@ns.sympatico.ca">jon-percy@ns.sympatico.ca</A> =
</DIV>
<DIV><B>Sent:</B> Wednesday, September 30, 2009 9:26 AM</DIV>
<DIV><B>Subject:</B> AFNS - Geology and Sea Level Change Field =
Trip.</DIV></DIV>
<DIV><BR></DIV>
<P>Hi AFNSers and Friends;</P>
<P>The following includes more details about the Geology and Sea Level =
Change=20
Field Trip planned for this Saturday October 3rd. We will meet half hour =
earlier=20
than originally planned - it is now 9:30 a.m. at the End of the Line Pub =
in=20
Bridgetown. Also, Tim suggests we bring bag lunches as he expects to =
finish by=20
about 3 p.m. If you are interested in participating it is important that =
you let=20
Gini (638-8353 or <A=20
href=3D"mailto:gproulx@eastlink.ca">gproulx@eastlink.ca</A> ) or =
I =20
(532-5129 or <A=20
href=3D"mailto:jon-percy@ns.sympatico.ca">jon-percy@ns.sympatico.ca</A> =
) know=20
<STRONG><FONT color=3D#ff0000>as soon as possible and <U>by Friday =
afternoon at=20
the latest</U></FONT></STRONG>. The trip may be cancelled if there is=20
insufficient interest. This is open to all, so please forward this to =
anyone you=20
think may be interested.</P>
<P>Cheers</P>
<P>Jon</P>
<P>>>>>>>>>>>>>>>>>>&g=
t;>>>>>>>>>>>>></P>
<DIV dir=3Dltr align=3Dleft><SPAN class=3D761472914-29092009>
<P style=3D"TEXT-ALIGN: center; MARGIN: 0in 0in 0pt" class=3DMsoNormal=20
align=3Dcenter><B style=3D"mso-bidi-font-weight: normal"><SPAN=20
style=3D"FONT-SIZE: 11pt">North Mountain Field Trip: Examples of the =
different=20
volcanic flow units and evidence of past higher sea-levels and possible =
future=20
sea-level rise impacts<o:p></o:p></SPAN></B></P>
<P style=3D"TEXT-ALIGN: center; MARGIN: 0in 0in 0pt" class=3DMsoNormal=20
align=3Dcenter><B style=3D"mso-bidi-font-weight: normal"><SPAN=20
style=3D"FONT-SIZE: 11pt"><o:p> </o:p></SPAN></B></P>
<P style=3D"TEXT-ALIGN: center; MARGIN: 0in 0in 0pt" class=3DMsoNormal=20
align=3Dcenter><B style=3D"mso-bidi-font-weight: normal"><SPAN=20
style=3D"FONT-SIZE: 11pt">Tim Webster, PhD<o:p></o:p></SPAN></B></P>
<P style=3D"TEXT-ALIGN: center; MARGIN: 0in 0in 0pt" class=3DMsoNormal=20
align=3Dcenter><B style=3D"mso-bidi-font-weight: normal"><SPAN=20
style=3D"FONT-SIZE: 11pt">Applied Geomatics Research=20
Group<o:p></o:p></SPAN></B></P>
<P style=3D"TEXT-ALIGN: center; MARGIN: 0in 0in 0pt" class=3DMsoNormal=20
align=3Dcenter><B style=3D"mso-bidi-font-weight: normal"><SPAN=20
style=3D"FONT-SIZE: 11pt">COGS, Middleton<o:p></o:p></SPAN></B></P>
<P style=3D"TEXT-ALIGN: center; MARGIN: 0in 0in 0pt" class=3DMsoNormal=20
align=3Dcenter><B style=3D"mso-bidi-font-weight: normal"><SPAN=20
style=3D"FONT-SIZE: 11pt"><A=20
href=3D"mhtml:{5BF2AADA-9C58-42FA-82CB-654C1E641EBE}mid://00000009/!x-usc=
:mailto:timothy.webster@nscc.ca">timothy.webster@nscc.ca</A><o:p></o:p></=
SPAN></B></P>
<P style=3D"TEXT-ALIGN: center; MARGIN: 0in 0in 0pt" class=3DMsoNormal=20
align=3Dcenter><B style=3D"mso-bidi-font-weight: normal"><SPAN=20
style=3D"FONT-SIZE: 11pt">825 5475<o:p></o:p></SPAN></B></P>
<P style=3D"TEXT-ALIGN: center; MARGIN: 0in 0in 0pt" class=3DMsoNormal=20
align=3Dcenter><B style=3D"mso-bidi-font-weight: normal"><SPAN=20
style=3D"FONT-SIZE: 14pt"><o:p> </o:p></SPAN></B></P>
<P style=3D"MARGIN: 0in 0in 0pt" class=3DMsoNormal><SPAN =
style=3D"FONT-SIZE: 11pt">The=20
<st1:place w:st=3D"on"><st1:PlaceName w:st=3D"on">North</st1:PlaceName>=20
<st1:PlaceType w:st=3D"on">Mountain</st1:PlaceType></st1:place> is =
comprised of=20
three volcanic flow units and was erupted from fissure volcanoes during =
the=20
Triassic period, 200 Million Years ago. The three volcanic flow units =
are quite=20
distinct and have variable resistance to erosion. As a result the =
morphology=20
(shape) of the <st1:place w:st=3D"on"><st1:PlaceName=20
w:st=3D"on">North</st1:PlaceName> <st1:PlaceType=20
w:st=3D"on">Mountain</st1:PlaceType></st1:place> reflects these =
differences in=20
erodability of the flow units. The lower flow unit (oldest) is exposed =
along the=20
south face of the North M Mountain and is quite thick, massive with =
columnar=20
joints and very resistant to erosion. The resistance to erosion of this =
unit is=20
in part why we have such a steep slope on the north side. The lower flow =
unit is=20
overlaid by the Middle Flow unit which is comprised of several thin =
volcanic=20
flows that are highly vesicular (gas bubbles). These air bubbles have =
been=20
subsequently in filled with zeolite minerals as a result of ground water =
circulation through the rocks. Stilbite, <st1:State =
w:st=3D"on"><st1:place=20
w:st=3D"on">Nova Scotia</st1:place></st1:State>=92s mineral, is one such =
mineral=20
that infill=92s these voids in the rocks.<SPAN style=3D"mso-spacerun: =
yes"> =20
</SPAN>Zeolites have a unique crystal structure and grow radially =
outward. The=20
Middle Flow unit is less resistant to erosion and is often referred to =
as=20
=93rotten rock=94 by local construction operators. The Upper Flow unit =
overlies the=20
Middle Flow Units and is similar to the lower flow unit in that it is =
resistant=20
to erosion and often outcrops along the <st1:place =
w:st=3D"on"><st1:PlaceName=20
w:st=3D"on">Bay of Fundy</st1:PlaceName> <st1:PlaceType=20
w:st=3D"on">Coast</st1:PlaceType></st1:place>.<o:p></o:p></SPAN></P>
<P style=3D"MARGIN: 0in 0in 0pt" class=3DMsoNormal><SPAN=20
style=3D"FONT-SIZE: 11pt"><o:p> </o:p></SPAN></P>
<P style=3D"MARGIN: 0in 0in 0pt" class=3DMsoNormal><SPAN =
style=3D"FONT-SIZE: 11pt">The=20
flow units have been mapped with the aid of a new remote sensing =
technique known=20
as LiDAR, Light Detection & Ranging. We use a laser onboard an =
aircraft to=20
precisely measure the earth=92s topography (lay of the land) to an =
accuracy of 15=20
cm in the vertical. The measurements are then used to construct a =
continuous=20
surface known as a Digital Elevation Model (DEM). We then use these DEM =
in the=20
computer to better visualize the subtle topographic changes of the land =
surface.=20
As a result we can see the contacts between the flow units and other =
interesting=20
landforms including raised terraces along the <st1:place w:st=3D"on">Bay =
of=20
Fundy</st1:place> that represent higher sea-levels. After deglaciation =
12-15,000=20
years ago, the sea-level rose faster than the earth=92s crust rebounded. =
Evident=20
of this high sea level is found at several locations along the coast in =
the form=20
of terraces. Recent tide gauge records from <st1:place =
w:st=3D"on"><st1:City=20
w:st=3D"on">Saint John</st1:City>, <st1:State =
w:st=3D"on">NB</st1:State></st1:place>=20
indicate relative sea-level is rising by 22 cm per century. This is a=20
combination of crustal subsidence and global sea-level rise. We have =
also used=20
these new LiDAR elevation models to map the town of <st1:City=20
w:st=3D"on"><st1:place w:st=3D"on">Annapolis =
Royal</st1:place></st1:City> and=20
project possible flood limits based on storm surges and future =
projections of=20
higher sea-levels. The Groundhog Day storm of 1976 was used a bench mark =
storm=20
and the flood extent was mapped using the LiDAR DEM. Future sea-level =
rise=20
projections were then used with this storm to predict what areas are at =
risk if=20
the storm were to reoccur in the future.<o:p></o:p></SPAN></P>
<P style=3D"MARGIN: 0in 0in 0pt" class=3DMsoNormal><SPAN=20
style=3D"FONT-SIZE: 11pt"><o:p> </o:p></SPAN></P>
<P style=3D"MARGIN: 0in 0in 0pt" class=3DMsoNormal><SPAN =
style=3D"FONT-SIZE: 11pt">The=20
field trip will begin with a presentation of the sea-level history of =
the area,=20
followed by an explanation of LiDAR and the improvements to topographic =
mapping=20
that it provides. Flood maps of <st1:place w:st=3D"on">Annapolis =
Royal</st1:place>=20
during the Groundhog Day storm and possible future flooding considering=20
sea-level rise will be shown. Maps of the <st1:place =
w:st=3D"on"><st1:PlaceName=20
w:st=3D"on">North</st1:PlaceName> <st1:PlaceType=20
w:st=3D"on">Mountain</st1:PlaceType></st1:place> will be displayed and =
the contact=20
between the flow units identified. In addition we will examine these =
raised=20
beach terraces that have resulted from past higher sea-levels. We will =
then=20
depart to visit the different volcanic flow units and contacts in the =
field and=20
the raised terraces along the coast.<o:p></o:p></SPAN></P></SPAN></DIV>
<DIV> </DIV>
<DIV align=3Dleft><FONT size=3D2 face=3DArial>
<P style=3D"MARGIN: 0in 0in 0pt" class=3DMsoNormal><SPAN=20
style=3D"FONT-FAMILY: Arial; FONT-SIZE: 10pt; mso-fareast-font-family: =
'Times New Roman'">Tim=20
Webster, Ph.D.</SPAN><SPAN=20
style=3D"FONT-FAMILY: Arial; FONT-SIZE: 8pt; mso-fareast-font-family: =
'Times New Roman'"><BR>Research=20
Scientist, Applied Geomatics Research Group (AGRG)<BR>Centre of =
Geographic=20
Sciences (COGS), <st1:place w:st=3D"on"><st1:PlaceName w:st=3D"on">Nova=20
Scotia</st1:PlaceName> <st1:PlaceType w:st=3D"on">Community=20
College</st1:PlaceType></st1:place><o:p></o:p></SPAN></P>
<P style=3D"MARGIN: 0in 0in 0pt" class=3DMsoNormal><SPAN=20
style=3D"FONT-FAMILY: Arial; FONT-SIZE: 8pt; mso-fareast-font-family: =
'Times New Roman'"> <o:p></o:p></SPAN></P>
<P style=3D"MARGIN: 0in 0in 0pt" class=3DMsoNormal><SPAN=20
style=3D"FONT-FAMILY: Arial; FONT-SIZE: 8pt; mso-fareast-font-family: =
'Times New Roman'">Chair,=20
Halifax Branch, Canadian Institute of Geomatics<o:p></o:p></SPAN></P>
<P style=3D"MARGIN: 0in 0in 0pt" class=3DMsoNormal><SPAN=20
style=3D"FONT-FAMILY: Arial; FONT-SIZE: 8pt; mso-fareast-font-family: =
'Times New Roman'">Adjunct=20
professor, <st1:place w:st=3D"on"><st1:PlaceName =
w:st=3D"on">Acadia</st1:PlaceName>=20
<st1:PlaceType w:st=3D"on">University</st1:PlaceType></st1:place>, Dept. =
of Earth=20
and Environmental Sciences<o:p></o:p></SPAN></P>
<P style=3D"MARGIN: 0in 0in 0pt" class=3DMsoNormal><SPAN=20
style=3D"FONT-FAMILY: Arial; FONT-SIZE: 8pt; mso-fareast-font-family: =
'Times New Roman'">Adjunct=20
professor, <st1:place w:st=3D"on"><st1:PlaceName=20
w:st=3D"on">Dalhousie</st1:PlaceName> <st1:PlaceType=20
w:st=3D"on">University</st1:PlaceType></st1:place>, Dept. of Earth=20
Sciences<o:p></o:p></SPAN></P></FONT></DIV></BODY></HTML>
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