45
the evening. Perhaps the biggest challenge was getting our Russian colleague Daria
to keep working; summer in Russia is a time of abundance and Daria loved nothing
more than downing tools at every opportunity to gather wild mushrooms and blueberries that made for a delicious evening meal. Other times fieldwork can be as
simple as visiting your local marsh; having a local project is a great way to get students into the field and engaging with local communities (Fig. 3.10).
The goal of fieldwork is to select a specific core (or set of cores) that are representative of the environmental and relative sea-level changes that took place over
the past few thousand years. These are then recovered and returned to a research
laboratory for analysis that often takes months and even years to complete. The
goals of this analysis are straight forward: determine (1) how high relative sea level
was and (2) when it was there. As always, the devil is in the detail. To figure out how
high relative sea level was we rely on reasoning by analogy. When the core is
unwrapped in the lab, it is first cut into 1-cm thick depth increments. Within these
sub-samples there are likely to be many hundreds of tiny foraminifera that are identified and counted under a microscope. On salt marshes there are just a handful of
species of foraminifera to learn how to identify, and once your eye is trained it is
possible to count them quite quickly, but the whole process will require many hours
at the microscope (a good opportunity to listen to an audio book). It is not unusual
for a project to require tens of thousands of individual foraminifera to be tallied. But
what do the foraminifera say about the height of relative sea level?
Previously we established that some of the species prefer to live at low elevations
and experience more frequent and longer duration submergence than other species
Fig. 3.6 A “Russian” type
core collected, fittingly,
from a salt marsh on the
White Sea in northwestern
Russia (hilariously, our
Russian colleagues call
this piece of kit a “Dutch”
corer). The unit of grey
sediment at the bottom of
the core is composed of
marine silt and clay that
was deposited below sea
level. The overlying unit is
salt-marsh peat that
includes the remains of
grasses and plants that
used to live at the site. This
transition from sub- to
inter-tidal environment
represents a relative
sea-level fall caused by
ongoing uplift of the land.
(Image by A.C. Kemp)
3 Time and Tide Wait for No Man
the evening. Perhaps the biggest challenge was getting our Russian colleague Daria
to keep working; summer in Russia is a time of abundance and Daria loved nothing
more than downing tools at every opportunity to gather wild mushrooms and blueberries that made for a delicious evening meal. Other times fieldwork can be as
simple as visiting your local marsh; having a local project is a great way to get students into the field and engaging with local communities (Fig. 3.10).
The goal of fieldwork is to select a specific core (or set of cores) that are representative of the environmental and relative sea-level changes that took place over
the past few thousand years. These are then recovered and returned to a research
laboratory for analysis that often takes months and even years to complete. The
goals of this analysis are straight forward: determine (1) how high relative sea level
was and (2) when it was there. As always, the devil is in the detail. To figure out how
high relative sea level was we rely on reasoning by analogy. When the core is
unwrapped in the lab, it is first cut into 1-cm thick depth increments. Within these
sub-samples there are likely to be many hundreds of tiny foraminifera that are identified and counted under a microscope. On salt marshes there are just a handful of
species of foraminifera to learn how to identify, and once your eye is trained it is
possible to count them quite quickly, but the whole process will require many hours
at the microscope (a good opportunity to listen to an audio book). It is not unusual
for a project to require tens of thousands of individual foraminifera to be tallied. But
what do the foraminifera say about the height of relative sea level?
Previously we established that some of the species prefer to live at low elevations
and experience more frequent and longer duration submergence than other species
Fig. 3.6 A “Russian” type
core collected, fittingly,
from a salt marsh on the
White Sea in northwestern
Russia (hilariously, our
Russian colleagues call
this piece of kit a “Dutch”
corer). The unit of grey
sediment at the bottom of
the core is composed of
marine silt and clay that
was deposited below sea
level. The overlying unit is
salt-marsh peat that
includes the remains of
grasses and plants that
used to live at the site. This
transition from sub- to
inter-tidal environment
represents a relative
sea-level fall caused by
ongoing uplift of the land.
(Image by A.C. Kemp)
3 Time and Tide Wait for No Man