Jacek Majorowicz1,2, Walter Skinner3, William Gosnold2 and Jan Safanda4

1
Heat energy gain over the past two decades in the
Canadian Prairies from repeated borehole
temperature logs
Jacek Majorowicz1,2, Walter Skinner3, William
Gosnold2 and Jan Safanda4 1 Northern Geothermal,
105 Carlson Close, Edmonton, Alberta, T6R 2J8,
Canada, Email majorowicz_at_shaw.ca,
Phone/Fax[phone] University of North
Dakota, Grand Forks, North Dakota, USA 3 Climate
Research Division, Environment Canada, Toronto,
Ontario, Canada 4 Institute of Geophysics, Bocni
II, Prague, Czech Republic
Introduction
The magnitude of heat storage is calculated for
the last 100 years, and the last 1-2 decades,
based on 40 individual well sites (some with
multiple boreholes) having 51 temperaturedepth
logs in the Canadian Prairies and for 5 repeated
logs (last 1-2 decades). Temperature transients
vs. depth are shown below. The heat needed to
warm the vertical column with a cross-section of
1 m2 in the depth interval 20 150 m for the
Canadian Prairies is 1.9E08 J. The change in
heat energy flux in Watts/m3 vs. depth is shown
below. The change calculated from repeated logs
is compatible (TSa13), mainly higher than change
calculated from all 51 single temperature logs in
Alberta and Saskatchewan, Canada
Temperature depth profiles (gt150m) in the
Canadian Prairie and U.S.A northern Great Plains
region have been interpreted to infer a very
strong ground surface temperature (GST) warming
over the past 100 years of 1 - 4ºC. In the
grassland areas of this region, the GST increases
are comparable to surface air temperature (SAT)
change from meteorological records.
Temperature-logs in boreholes, initially made one
to two decades ago, in the Canadian Prairies and
U.S.A northern Great Plains were recently
repeated. Jacek Majorowicz Jan Safanda, Measured
versus Simulated Transients of Temperature Logs -
a Test of Borehole Climatology. Journal of
Geophysics and Engineering 2(4) 291-298,
2005. Jacek Majorowicz, Walter Skinner, Jan
Safanda Will Gosnold, Differences between
repeated borehole temperature logs in the
southern Canadian Prairies-validating borehole
climatology. Clim. Past Discuss. 2 130,
2006. Heinle Shannon Will Gosnold, New
Measurements from Old Boreholes A Look at
Interaction Between Surface Air Temperature and
Ground Surface Temperature. Eos Trans. AGU,
88(52), Fall Meet. Suppl., Abstract PP11A-0216,
2007
The T-z transients forced by SAT match the
observed T-z transient from repeated log data
(see below example of well TSa13). Repeated
borehole logging allows for the extraction of
temperature differences over time such as those
shown for the wells located at the
Alberta-Montana border (see location map).
Modeling of the effects of SAT change on the
subsurface temperature regime shows that SAT
variability is the primary forcing mechanism for
the observed underground anomalous temperature
with depth profile and observed change in
temperature over time.

The synthetic T-z transients forced by SAT POM
(surface air temperature pre observational mean
level) match the observed T-z transient data from
repeated logs, while solar forcing based T-z
transients explain only a small portion of
observed underground heat gain. This
demonstrates that the large heat gain by the
ground cannot be fully explained by changes in
solar forcing. Other factors, such as greenhouse
gas forcing are likely responsible.

Data, Method and Results
Summary
There has been a distinct increase in western
Canadian surface air temperature (SAT) over the
past 100 years. The above time series represents
the average curve of several annual SAT anomaly
records in the Prairie Climate Region of western
Canada. Temperature logs from deep boreholes,
such as the example shown here in southern
Alberta, can be used to estimate ground warming
over time periods spanning decades to centuries.
Repeated logs of temperature with depth (time)
show anomalous curvature in the upper 100 m and
progressive warming of the subsurface with time
as shown in upper two panels in the next figure.
SAT forcing is primarily responsible for the
underground temperature changes diffusing with
depth. Solar forcing - climatic surface forcing
at assumed sensitivities can only account for the
fraction of the last 100 years warming registered
underground by 51 Prairie logs from 40 wells. The
discrepancy between solar based T-z transients
calculated in this paper and those observed from
well logs begin at about 100m which we relate to
the last 5 decades /- 10 years. This is
equivalent to the timing of increased warming
due to other factors. The most likely factor is
the dramatic increase in greenhouse gases.
Surface warming of this magnitude causes the
Earth to store large amount of heat. Observed
anomalies of temperature with depth show that
large amounts of heat have been stored
underground. SAT variability, and the
pre-observational SAT minimum related to the
Little Ice Age (LIA) from the 17th to 19th
centuries, are largely responsible for the large
ground surface temperature (GST) warming trends
and closely parallel SAT trends recorded at
nearby meteorological stations but significantly
diverge from the trends in top of atmosphere
(TOA) solar irradiance.
Financial support 2007 2008 in part by