Page 9 - Shell_growth_2008

Geo-Mar Lett (2008) 28:309–325 317

Table 6 Cala Grande isotope and temperature (°C) data
18
Month Edge δ O SHELL Calculated Mean SST Difference, between Mean monthly Difference between
18
value (‰ VPDB) δ O SHELL measured at the measured SST SST at Mazara mean monthly SST at
18
temperature (°C) time of collection and δ O SHELL del Vallo (°C) Mazara del Vallo and
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(°C) temperature (°C) δ O SHELL temperature
November 2002 +0.84 20.9 20.4 −0.5 ns 18.7 −2.2
December 2002 +2.15 15.2 16.8 +1.6 16.2 +1.0
January 2003 +2.32 14.5 15.9 +1.4 15.5 +1.0
February 2003 +2.80 12.4 15.1 +2.7 14.4 +2.0
March 2003 +2.62 13.2 15.0 +1.8 14.6 +1.4
April 2003 +2.25 14.8 16.0 +1.2 15.6 +0.8 ns
May 2003 +1.34 18.7 18.8 +0.1 ns 17.5 −1.2
June 2003 +1.21 19.3 19.6 +0.3 ns 21.2 +1.9
July 2003 +0.55 22.2 25.0 +2.8 23.3 +1.1
August 2003 +0.50 22.4 24.7 +2.3 25.3 +2.9
September 2003 +0.21 23.7 25.9 +2.2 24.1 +0.4 ns
October 2003 +1.16 19.5 21.9 +2.4 22.6 +3.1
November 2003 +1.23 19.2 19.5 +0.3 ns 20.1 +0.9
December 2003 +1.27 19.0 18.9 −0.1 ns 17.2 −1.8
January 2004 +2.11 15.4 14.5 −0.9 14.9 −0.5 ns
February 2004 +2.37 14.2 14.9 +0.7 ns 14.4 +0.2 ns
March 2004 +2.42 14.0 14.9 +0.9 14.6 +0.6 ns
April 2004 +2.69 12.9 15.5 +2.6 15.3 +2.4
May 2004 +2.31 14.5 16.9 +2.4 17.3 +2.8
June 2004 +1.93 16.2 19.7 +3.5 19.9 +3.7
July 2004 +0.92 20.6 20.6 0.0 ns 22.1 +1.5
August 2004 +0.28 23.3 24.9 +1.6 23.8 +0.5 ns
September 2004 +0.36 23.0 25.6 +2.6 23.2 +0.2 ns
October 2004 +0.47 22.5 23.4 +0.9 21.9 −0.6 ns

ns Not statistically significant

Fig. 6 Monte Cofano: fluctua-
tions over 2 years in surface
seawater temperatures at the
locality (filled symbols), and
temperatures calculated from
18
δ O SHELL values (open sym-
bols) derived from shell edges
(one shell was analysed each
month)