Figures for Sean Mewhinney's Minds in Ablation
Figure 1-1 (21K).
Delta 18O values of snow plotted against temperatures
for sites in various regions of Greenland and
Antarctica. Both figures are annual averages.
Source: W. Dansgaard et al.,, "Stable
Isotope Glaciology," Meddelelser om
Grønland, Vol. 197, no. 2 (1973).
Figure 1-2a (17K).
Comparison of the Devils Hole and
Vostok stable isotope paleotemperature records. For Vostok
we show both the original chronology of Lorius et al.
(1985) and the more recent EGT ("extended glaciological
time scale") chronology of Jouzel et al., (1993). The
linear correlation (r) of Devils Hole with the Lorius
chronology in 0.92, and 0.95 with the EGT chronology; no phase
adjustments have been made. Standard deviation units computed
over the time interval shown.
Source: Isaac J. Winograd et al., "Duration and Structure
of the Past Four Interglaciations," Quaternary Research
Vol. 48 (1997), pp. 141-154.
Figure 1-2b (18K).
Comparison of the Devils Hole and SPECMAP 
18O time series.
The linear correlation (r) between these records is -0.50;
no phase adjustments have been made. Marine isotope substages
are labeled in the figure. Standard deviation units computed over
the full record. Following standard practice in the paleoclimatologic
literature, the sign of the SPECMAP time series has been switched
(note minus sign) so that interglaciations appear as peaks.
Source: Isaac J. Winograd et al., "Duration and Structure
of the Past Four Interglaciations," Quaternary Research
Vol. 48 (1997), pp. 141-154.
Figure 2-1 (51K).
Departures of: (a) summer temperature (°C),
(b) annual precipitation (mm), from modern values
for the Holocene climatic optimum (Borzenkova and
Zubakov, 1984; Budyko and Izrael, 1987).
Source: J. T. Houghton et al., eds.,
Climate Change: The IPCC Scientific Assessment
(Cambridge U. Pr., 1990).
Figure 2-2 (44K).
ANNUAL MEAN TEMPERATURE.
Deviations from present-day values
by V. A. Klimanov.
HOLOCENE: (about 6,000 to 5,500 yr B.P.)
Source: B. Frenzel et al., Atlas of Paleoclimates and
Paleoenvironments of the Northern Hemisphere: Late
Pleistocene-Holocene (Budapest & Stuttgart, 1992).
Figure 3-1 (41K).
Location map of northern Canada showing the tentative reconstruction
of the most northerly mean summer position of the Arctic Front
during the hypsithermal. These smoothed curves connect locations
of relict spruce clones which are thought to represent the
northernmost extension of the forest-tundra ecotone. The palynological
sites bracketing the ecotone contain evidence of prolonged
Holocene tundra conditions (Pelly Lake, Coppermine) or
micro- and macro-fossil proof of substantial northward displacement
of the forest.
Source: Harvey Nichols, Palynological and Paleoclimatic Study
of the Late Quaternary Displacements of the Boreal Forest-Tundra
Ecotone in Keewatin and Mackenzie, N.W.T., Canada, Institute
of Arctic and Alpine Research Occasional Paper 15 (1975).
Figure 3-2 (60K).
Vegetation map for the second half of the Atlantic period,
6000-4600 yr B.P. (Compiled by N. A. Khotinskiy with the use of data
by M. I. Neustadt, T. A. Serebryannaya, A. T. Artyushenko,
A. A. Seybutis, O. F. Yakushko, G. A. Yelina, L. D. Nikiforova,
V. S. Volkova, G. M. Levkovskaya, M. V. Nikol'skaya, V. A. Belova,
A. I. Tomskaya, T. D. Boyarskaya, T. N. Kaplina, and A. V. Loshkin.)
Source: N. A. Khotinskiy, "Holocene Vegetation History," in
A. A. Velichko et al., eds., Late Quaternary Environments
of the Soviet Union (Univ. of Minnesota Press, 1984), pp. 194-195.
Figure 3-2b (60K).
Key to Figure 3-2: The most relevant indicators are,
in the north, the boundary betweem tundra (1) and forest tundra (2),
and the southern limit of tundra (19), and in the east, the border
between mountain tundra and shrubland (17) and light larch taiga (6a).
Figure 3-3 (72K).
Vegetation regions reconstructed from pollen data
for 9000, 6000, 3000, and 0 B.P. (See Table 7.1
for reconstruction criteria.)
Source: Brian Huntley and I. Colin Prentice,
"Holocene Vegetation and Climates of Europe,"
in H. E. Wright et al., eds.,
Global Climates Since the Last Glacial Maximum
(Univ. of Minnesota Press, 1993), p. 147.
Figure 3-4 (31K).
Forest and grassland limits on the plains of
North America and Eurasia about 2000 B.C. and
at the present day.
(Sources used include FRENZEL
(1966, 1967), NEISTADT
(1957), and NICHOLS
(1967a).)
Source: H. H. Lamb, Climate: Present, Past and Future
(London & N.Y., 1977),
Vol. 2: Climatic History and the Future.
Figure 3-5 (63K).
Skille Valley and terminal segment of
Skille Glacier, Clavering Island. Base traced,
with modifications, from map, "Claveringgöya;
1:100,000," in O. Lacmann: Karte von
Nordostgrönland, Gotha, 1937.
Source: Louise A. Boyd, The Coast of Northeast
Greenland, American Geographical Society
Special Publication no. 30 (N.Y., 1948), p. 129.
Figure 3-6 (39K).
Clavering Island and vicinity.
Figure 4-1 (16K).
Generalized cross-section of glacier facies.
The snow cover is completely stripped away
in the ablation facies. The entire year's
accumulation is raised to the melting point
and wetted in the soaked facies. In the
percolation facies the annual increment of
new snow is not completely wetted nor raised
to the melting point, and the amount of
percolation decreases with altitude, becoming
negligible at the dry snow line.
Negligible melt occurs in the dry snow facies.
Source: Carl S. Benson, Stratigraphic Studies
in the Snow and Firn of the Greeland Ice Sheet
(U.S. Army Snow, Ice, and Permafrost Research
Establishment Research Report 70, July, 1962).
Figure 4-2 (60K).
Distribution of diagenetic facies on the Greenland
Ice Sheet.
Source: Carl S. Benson,
Stratigraphic Studies in the Snow and Firn
of the Greeland Ice Sheet (U.S. Army Snow,
Ice, and Permafrost Research Establishment
Research Report 70, July, 1962).
Figure 4-3 (12K).
Idealized cross-section of an ice sheet.
The horizonal lines represent annual layers,
which thin progressively as they sink toward
the base of the ice sheet. The central
vertical line I-I represents an ice divide.
The curved lines show the direction of ice flow
downward from the site of deposition and outward
toward the margin.
"When the equilibrium line (the line where
the annual loss of ice by melting exactly
balances the annual mass input by snow
deposition) is reached, the ice layers begin to
move up relative to the surface and then resurface
downslope from the equilibrium line. The further
inland the ice was originally deposited, the
closer to the ice margin the ice will reappear,
and the older the surface ice will be."
Quotation from M. Maurette et al.,
"Placers of Cosmic Dust in the Blue Ice Lakes
of Greenland," Science, August 22, 1986,
p. 870. The arrows to the left of the vertical
line C-C represent the horizontal velocity of the
ice at different depths, which falls to zero
at the bottom for an ice sheet frozen to its bed.
Source of illustration: W. Dansgaard et al.,
"Climatic Record Revealed by the Camp Century Ice Core,"
in Karl Turekian, ed., The Late Cenozoic Glacial
Ages (Yale Univ. Press, 1971).
Figure 4-4 (45K).
Isotherms of mean annual temperature and surface
elevation contours for the Greenland ice sheet,
together with seasonal temperature-depth profiles.
The ice thickness in metres (Z) is shown
at each profile site except Camp Century where
data to bedrock was obtained.
Temperature-depth profiles:
Camp Century (see also Table 4.1): B. L. Hansen
(personal communication); Weertman (1968).
Site2: Hansen and Landauer (1958).
Camp VI: Heuberger (1954).
Milcent: B. L. Hansen (personal communication).
Station Centrale: Heuberger (1954).
Crete: B. L. Hansen (personal communication).
Jarl Joset: Philberth (1970).
Dye 3: B. L. Hansen (personal communication).
Source: G. de Q. Robin, ed., The Climatic Record
in Polar Ice Sheets (Cambridge Univ. press, 1983).
Figure 5-1 (36K).
"Amorphous Blob Number One": Schematic world
map in a 15th-century edition of Macrobius.
Figure 5-2 (64K).
A Ptolemaic world map.
Figure 5-3 (59K).
The 1506 world map of Giovanni Contarini.
Figure 5-4 (48K).
The Lopo Homem world map of 1519.
Figure 5-5a (45K).
Francesco Rosselli, world map, ca. 1508.
Figure 5-5b (53K).
Francesco Rosselli, oval planispheric world map, ca. 1508.
Figure 5-6 (45K).
The "da Vinci" gores.
Figure 5-7a (79K).
Gores from the southern hemisphere of Johann
Schöner's 1515 globe.
Figure 5-7b (55K).
A hemisphere of Johann Schöner's globe of 1520.
Figure 5-8 (65K).
The "Rosenthal" or "Munich" gores, printed in Nuremburg ca. 1540.
Figure 5-9 (63K).
Francesco Ghisolfi, 16th-century world map.
Figure 5a-1 (85K).
The Zeno map.
Figure 5a-2 (52K).
Mallery's doctored version of the Zeno map with "Icaria"
greatly enlarged, rotated slightly, and repositioned to the east.
Source: The Rediscovery of Lost America.
Figure 5a-3 (55K).
Mallery's closeup of Greenland and Iceland from the Zeno map, overlaid
with the outline of Greenland from a modern map. The dashed line
represents the coastline of Greenland from the modern map. The hatched
area represents former land now submerged, and the stippled area marked
"Fiordr Ollum Lengri" represents former sea now covered by the
Greenland ice sheet, according to Mallery. It appears in
Lost America as "Map of Greenland and Gunnbiorn's Skerries."
Figure 5a-4 (111K).
Part of the east coast of Greenland overlaid with Iceland from the
Zeno map (dotted line). This version is taken from Lost America
(1950).
Figure 5a-5 (72K).
Contour map of the subglacial bedrock of Greenland prepared by
the Expéditions Polaires Françaises.
Source: Jean-Jacques Holtzscherer, "Contribution à la
Connaissance de l'Inlandsis du Groenland, Première Partie:
Mesures Séismiques," International Association of
Hydrological Sciences, Assemblée Générale,
Rome (1954), Vol. 4 (I.A.H.S. Publication no. 39).
Figure 5a-6 (28K).
A subglacial topographic map of Greenland, showing the
sea-level contour.
Source: Charles Hapgood, Maps of the Ancient Sea Kings,
2nd ed., (1979), p. 131.
Figure 5a-7 (61K).
Top: Map of Dronning Maud Land, Antarctica, showing the route
followed by a seismic survey in 1953. Bottom: Vertical profile
of the survey line, reduced to a common scale, which I have
modified by adding a solid line at an elevation of 200 meters
above sea level, and below it, a bar indicating bedrock elevations
above (hatched) and below (blank) this level.
Source: The Geographical Journal Vol. 120, no. 2 (June, 1954).
Figure 5a-8 (27K).
An enlargement of the lower right-hand corner of Charles Hapgood's
reproduction of the Piri Re'is map from Maps of the Ancient
Sea Kings. When comparing with
Fig. 5a-7, remember that confusingly,
Hapgood has given the grid on this part of the map both
latitude and longitude readings which are wrong, according to him!
So one must subtract 10 degrees from the west longitude readings
at the bottom, while all the latitudes are too far north, even
after adding a correction of 25 degrees to the main grid.
Hapgood gives the followed numbered features these identifications:
80.: Mt. Ropke, 81.:
Regula Range, 82.: Muhlig-Hofmann Mtns., 83.: Penck Trough,
84.: Neumayer Escarpment, 85.: Drygalski Mtns.,
86.: Vorposten Peak, 87.: Boreas, Passat Nunataks.
Figure 6-1 (45K).
According to Charles Ginenthal, these lakes are quite probably
meteorite craters.
Source: George Plafker, "Oriented Lakes and Lineaments of Northeastern Bolivia,"
Geological Society of America Bulletin Vol. 75 (June, 1964),
pp. 503-522, Plate 3.
Figure 6-2 (36K).
Oxygen isotope composition, dust content and alkalinity
versus depth for the lowest 250 meters of the Dye 3
Greenland ice core [Hammer et al., 1985]. The time interval
covered by this section is approximately 8000-80,000
years ago [Dansgaard et al., 1982]. Cold events appear as
more negative 18O
values and are correlated with
increased dust content.
Figure 6-3a (39K).
From the top down, a and b,
oxygen isotope ratios of enclosed air in the GISP2 and Vostok
ice cores from Greenland and Antarctica, respectively;
c, oxygen isotope ratios in a marine sediment
core; d, hydrogen isotope ratios in the
Vostok ice core; e, oxygen isotope ratios in
the GISP2 ice core; f, calcium concentrations
in the GISP2 core shown on a logarithmic scale, which serves
as a proxy of dustiness. The dotted lines show warming events
identified in both Greenland and Antarctica.
Source: Michael Bender et al., "Climate Correlations
Between Greenland and Antarctica During the Past 100,000 Years,"
Nature Vol. 372 (Dec. 15, 1994)), p. 664.
Figure 6-3b (39K).
From the top down, the first and third curves show carbon dioxide
and methane in the air enclosed in the ice core from Vostok, Antarctica.
The second curve represents changes in temperature at the top of the
inversion layer over Vostok as deduced from isotope ratios of the ice.
The curve at the bottom shows oxygen-isotope ratios in a marine
sediment core.
Source: Claude Lorius and Jean Jouzel, "European Project for Ice Coring
in Antarctica (EPICA)," in G. Hempel, ed., The Ocean and
the Poles (Gustav Fischer, 1995), p. 268.
Figure 6-3c (23K).
Methane concentrations in the enclosed air of the GRIP ice core
from Greenland and the Byrd Station ice core from Antarctica.
Source: B. Stauffer et al., "Atmospheric CO2
Concentration and Millennial-Scale Climate Change During the
Last Glacial Period," Nature Vol. 392 (March 5, 1998),
pp. 59-62.
Figure 6-3d (49K).
e, at the bottom, methane concentrations in the
GRIP and Byrd Station ice cores from Greenland and Antarctica,
this time on a common age scale instead of depth scales;
a, at the top, oxygen isotope ratios in the
GRIP ice core with numbered warming events; below that, Heinrich
events 2 to 5, on the vertical dashed lines; b,
abundances of the foraminifer N. pachyderma in a
North Atlantic sediment core as a proxy for sea-surface
temperatures; d, carbon dioxide concentrations
in the Byrd ice core. Note the correlation of warm periods
with methane peaks.
Source: B. Stauffer et al., "Atmospheric CO2
Concentration and Millennial-Scale Climate Change During the
Last Glacial Period," Nature Vol. 392 (March 5, 1998),
pp. 59-62.
Figure 6-4a (10K).
Atlantic Shivers: The European ice core records large swings
in air temperature over Greenland during the most recent ice age.
Dashed lines highlight cycles of successively weaker warmings,
followed by large temperature peaks. During the coldest periods,
known as Heinrich events (labelled H1 through H6), fleets of
icebergs floated across the ocean.
Figure 6-4b (23K).
From the top down: oxygen isotope ratios in planktonic (near-surface)
foraminifera from a North Atlantic sediment core; abundances of the
cold-water foraminifera N. pachyderma in two North Atlantic
cores; Heinrich ice-rafting events 1 to 6; oxygen isotope ratios
in the GRIP ice core; asymmetric sawtooth-shaped cooling cycles
and numbered interstadial warming events.
Source: Gerard Bond et al., "Correlations Between Climate
Records from North Atlantic Sediments and Greenland Ice,"
Nature Vol. 365 (Sept. 9, 1993), p. 145.
Figure 6-5 (36K).
On the left, percentage of pine in a pollen sequence from
Lake Tulane, Florida. Right, concentrations of ice-rafted
debris in a North Atlantic sediment core. Heinrich events
1 to 5 are numbered. Wet periods in Florida correlate
with ice discharges in the North Atlantic.
Source: Eric C. Grimm et al., "A 50,000-Year Record
of Climate Oscillations from Florida and Its Temporal Correlation
with the Heinrich Events," Science Vol. 261 (July 9, 1993),
p. 199.
Figure 6-6 (36K).
On the left, oxygen isotope ratios in the GISP2 ice core from
Summit, Greenland. Middle, an index of bioturbation in a
sediment core from the Santa Barbara basin off the California
coast, ranging from one -- distinct, continuous laminations
with no bioturbation, to four -- completely bioturbated,
fine-grained sediment, presented as a 49-centimeter running
average. Right, oxygen isotope ratios in benthic (deep-water)
foraminifera in the Santa Barbara core. The ice-core and
marine chronologies were derived independently. At least
16 of the 17 warm interstadials in the Greenland ice core can
be clearly seen in laminated sections of the Santa Barbara
core.
Source: Richard J. Behl and James P. Kennett,
"Brief Interstadial Events in the Santa Barbara Basin,
NE Pacific, During the Past 60 kyr," Nature Vol.
379 (Jan. 18, 1996), p. 244.
Figure 6-7 (36K).
Top left, inferred sea-surface temperatures in a North Atlantic
sediment core. Middle, oxygen isotope ratios in the GRIP
ice core from Summit, Greenland. Right, a gray scale of sediment
in a core from the Cariaco basin off Venezuela. Light-colored
sediment, indicating greater biological productivity, is correlated
with cold periods in Greenland and the North Atlantic. Bottom left,
oxygen isotopes in the GRIP ice core for the period 12,600 to
13,600 years ago, encompassing the Older Dryas and the
inter-Alleroed cold periods. Bottom right, thickness in millimeters
of laminations in the Cariaco basin core. Greater thickness
indicates greater biological productivity, again correlated
with cold periods in Greenland.
Source: Konrad A. Hughen at al., "Rapid Climate Changes
in the Tropical Atlantic Region During the Last Deglaciation,"
Nature Vol. 380 (March 7, 1996), p. 53.
Figure 6-8 (18K).
Oxygen isotope ratios in carbonate from a Swiss lakebed and the
Dye 3 ice core.
Source: Hans Oeschger, "Long-Term Climate Stability:
Environmental System Studies," in S. Fred Singer, ed.,
The Ocean in Human Affairs (N.Y., Paragon House, 1990),
p. 64.
Figure 6-9a (37K).
Two sediment cores from Crawford Lake, west of Lake Ontario.
At left, age scale in radiocarbon years and depth in centimeters.
Center, oxygen-isotope ratios of lakebed carbonate. To the right,
spruce (Picea) and pine (Pinus) pollen abundance.
Far right, pollen assemblage zones (PAZ) and inferred vegetation
types.
Source: Zicheng Yu and Ulrich Eicher, "Abrupt Climate Oscillations
During the Last Deglaciation in Central North America,"
Science Vol. 282 (Dec. 18, 1998), pp. 2235-2238.
Figure 6-9b (22K).
Oxygen-isotope curves from the GISP 2 ice core in Greenland
at left and Crawford Lake on the right. The GISP2 time scale from
counting annual layers is given in calendar years. The Crawford Lake
time scale is in uncorrected radiocarbon years.
Source: Zicheng Yu and Ulrich Eicher, "Abrupt Climate Oscillations
During the Last Deglaciation in Central North America,"
Science Vol. 282 (Dec. 18, 1998), pp. 2235-2238.
Figure 6-10 (18K).
Oxygen-isotope compositions of the GRIP and GISP2
deep ice cores. The shallowest overturned folds, and the
shallowest two regions of steep dips, are indicated for each core.
The depths of major features in the cores differ slightly owing
to well-understood differences in snow accumulation and layer
thinning; significant mismatch not explainable in this way occurs
deeper than about 2,700-2,750 m.
Source: R. B. Alley et al., "Comparison of Deep Ice Cores,"
Nature Vol. 373 (Feb. 2, 1995), p. 394.
Figure 6-11 (33K).
The sources of North Atlantic Deep Water. Overflow from the
Greenland, Iceland, and Norwegian Seas combines with Labrador
Sea Deep Water to form the Deep Western Boundary Current.
Source: Bruce A. Warren, "Deep Circulation of the World Ocean,"
in Bruce A. Warren and Carl Wunsch, eds.,
Evolution of Physical Oceanography: Scientific Essays
in Honor of Henry Stommel (Cambr., Mass., M.I.T. Press, 1981), p. 23.
Figure 6-12 (44K).
Cadmium concentrations at different depths in the North Atlantic over
the past 24,000 years, inferred from measurements on benthic foraminifera.
Top: from a core at 4,450 meters' depth; bottom: from a core at
965 meters. High cadmium concentrations imply sluggish circulation.
Note that the circulation of North Atlantic Deep Water (NADW) strengthens
during the course of deglaciation, while the circulation of Glacial
North Atlantic Intermediate Water (GNAIW) weakens, with a reversal
of these trends during the Younger Dryas cold period.
Source: Thomas M. Marchitto, Jr., William B. Curry, and Delia W. Oppo,
"Millennial-Scale Changes in North Atlantic Circulation Since the
Last Glaciation," Nature Vol. 393 (June 11, 1998), pp. 557-561.
Figure 6-13 (35K).
Fluctuations in relative bottom-current speed over the past
25,000 years off the northeastern United States, as indicated
by mean silt particle size expressed in phi units
(the smaller the number, the larger the particle size,
and the stronger the current). The data for each deep-sea
sediment core are plotted directly above the position of
the core on a profile of the continental slope and rise shown below.
The modern position of the Deep Western Boundary Undercurrent
(DWBUC) is shown for reference.
Source: Michael T. Ledbetter and William L. Balsam,
"Paleoceanography of the Deep Western Boundary Undercurrent
on the North American Continental Margin for the Past 25000 Yr,"
Geology Vol. 13 (March, 1985), p. 183.
Figure 6-14 (25K).
Reconstructed past sea-surface salinity in the northeast Atlantic,
A (top), in the summer, and B
(bottom), in winter. The thin solid line was calculated assuming
a mean oxygen-isotope ratio of -20%o
for glacial meltwater, and
the discontinuous dotted line, assuming a ratio of
-35%o during
Heinrich events only. The heavy solid line near the top in both
figures represents global mean ocean salinity.
Source: M. A. Maslin, N. J. Shackleton, and U. Pflaumann,
"Surface Water Temperature, Salinity, and Density Changes
in the Northeast Atlantic During the Last 45,000 Years:
Heinrich Events, Deep Water Formation, and Climatic Rebounds,"
Paleoceanography Vol. 10, no. 3 (June, 1995), pp. 527-544.
Figure 6-15 (28K).
The smoothly curving, parallel lines near the top of both figures
represent the estimated range of possible density of North
Atlantic Deep Water between the temperature extremes of 1 and
3 degrees Celsius. The jagged solid line in figure A,
above, represents the calculated density of surface water at the
core site in the northeast Atlantic. Note that density drops
steeply during Heinrich events (H1 to H4 in the figure). The
jagged lines in figure B, below, represent the
density of this surface water if cooled a further 1 degree
(bottom line) or 6 degrees Celsius (top line) as it flows
northward. Deep-water formation is only possible during the
periods between the downward-pointing arrows, when density
rises above the critical threshhold.
Source: M. A. Maslin, N. J. Shackleton, and U. Pflaumann,
"Surface Water Temperature, Salinity, and Density Changes
in the Northeast Atlantic During the Last 45,000 Years:
Heinrich Events, Deep Water Formation, and Climatic Rebounds,"
Paleoceanography Vol. 10, no. 3 (June, 1995), pp. 527-544.
Figure 6-16 (30K).
A, top, gray-scale measurements of sediments
in the Cariaco basin, north of Venezuela. Sediments deposited
during the cold Younger Dryas period (YD) are lighter than
those of the preceding Boelling/Alleroed period (BA) and the
subsequent post-glacial period. B, bottom,
variation in atmospheric carbon-14, as calculated from
comparison of measured 14C
ages with calendar dates
of Cariaco basin sediments from counting annual laminations.
Note the increase of 50%o (5%)
in delta 14C
during the first 200 years of the Younger Dryas.
Source: Wallace S. Broecker, "Paleocean Circulation During
the Last Deglaciation: A Bipolar Seesaw?,"
Paleoceanography Vol. 13, no. 2 (April, 1998), pp. 119-121.
Figure 6-17 (30K).
Atmospheric carbon-dioxide concentrations for the period 11,500
to 9,600 radiocarbon years ago, reconstructed from stomatal density
measurements on willow leaves in sediments at Lake Kråkenes,
Norway. Individual measurements fall within the shaded area.
The bold line is statistically smoothed.
Source: David J. Beerling, Hilary H. Birks, and Ian F. Woodward,
"Rapid Late-Glacial Atmospheric CO2 Changes Reconstructed from
the Stomatal Density Record of Fossil Leaves,"
Journal of Quaternary Science Vol. 10, no. 4 (1995)
pp. 379-384.
Figure 7-1 (65K).
Northern-hemisphere ice sheets at their maximum extent during the
last glaciation, as reconstructed by George H. Denton and Terence J. Hughes,
eds., The Last Great Ice Sheets (Wiley, 1981). Ice-sheet
elevation contours are shown at 500-meter intervals. (The orientation
has been reversed to make comparison with Fig. 7-2 easier.)
Figure 7-2 (56K).
Present-day precipitation in Siberia in millimeters.
You may find a larger version (715K) more legible.
Source: Climatic Atlas of Asia, Vol. 1 (Geneva, 1981), plate 27A.
Figure 7-3 (31K).
Bottom (e): Dust concentration in the Vostok ice core
for the past ~420,000 years in parts per million. Top (a):
Hydrogen isotope ratios ( deuterium) --
the more negative the ratio, the colder the temperature.
Source: J. R. Petit et al., "Climate and Atmospheric History
of the Past 420,000 Years from the Vostok Ice Core, Antarctica,"
Nature Vol. 399 (June 3, 1999), Fig. 2, p. 430 (simplified).
Figure 7-4 (75K).
Dust in the GISP2 ice core for the period 14,000 to 10,500 years ago.
(A): Number of microparticles per milliliter of meltwater;
(B): Mass concentration of dust in parts per billion;
(C):Mean particle size, calculated based on the number of
particles;
(D):Mean particle size, based on particle mass.
(Compare the general shape of curves (A) and (B) with
Figs.
6-12,
6-16(b), and
6-17.)
Source: Gregory A. Zielinski and Grant R. Mershon,
"Paleoenvironmental Implications of the Insoluble Microparticle Record
in the GISP2 (Greenland) Ice Core During the Rapidly Changing Climate
of the Pleistocene-Holocene Transition,"
Geological Society of America Bulletin Vol. 109, no. 5
(May, 1997), Fig. 4, p. 553.
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