MID-HOLOCENE CLIMATE RECONSTRUCTION IN THE SOLEDAD BASIN ...jortiz/home... · The Soledad Basin...
1
MID-HOLOCENE CLIMATE RECONSTRUCTION IN THE MID-HOLOCENE CLIMATE RECONSTRUCTION IN THE SOLEDAD BASIN USING PLANKTIC FORAM ASSEMBLAGES SOLEDAD BASIN USING PLANKTIC FORAM ASSEMBLAGES (Presentation No. 75-25) (Presentation No. 75-25) WILSBACHER, Matthew C. 1 , ORTIZ, Joseph 1 , O'CONNELL, Suzanne 2 , ZHENG, Yan 3 , MARCHITTO, Tom 4 , CARRIQUIRY, Jose 5 , DEAN, Walter 6 , and VAN GEEN, Alexander 7 , (1) Dept. of Geology, Kent State University, Kent, OH 44242, [email protected], (2) E&ES, Wesleyan Univ, 265 Church St, Middletown, CT 06459, (3) School of Earth and Environmental Sciences, Queens College, C.U.N.Y, 65-30 Kissena Blvd, Flushing, NY 11365, (4) Lamont-Doherty Earth Observatory, Palisades, NY 10964, (5) Instituto de Investigaciones Oceanologicas, Universidad Autonoma de Baja California, Ensenada, Mexico, (6) USGS, Earth Surface Processes, Denver, CO 80225, (7) LDEO, Palisades, NY 10964 I Abstract The instrumental climate record for the subtropical Pacific is useful for reconstructing interannual climate variability, though it is limited by its short-term duration. Climate proxies from high-resolution sites can be used in extending this record to geologic time scales, but only if the proxies are properly calibrated. The Soledad Basin (SB) off the coast of Baja, California (25 O 12’ N, 112 O 43’ W) is a viable locale for constructing such proxies due to its high sedimentation rate, providing a temporal resolution of ~10 yr/cm. Here, we present a pilot study of modern analog temperature estimates based on planktic foraminiferal faunal assemblages from SB gravity (MV99-GC-41) and piston (MV99-PC-14) cores. The goal of this study is to explore whether productivity in the SB during the mid-Holocene, a period of strong summer insulation, was higher or lower than modern values. These faunal temperature estimates are calibrated against a 1083 sample data set (Ortiz et al., 1997) and 1995-1998 Santa Barbara Basin (34 O 14’N, 120 O 02’W) sediment trap faunas from Black et al. (2001). Comparing NCEP instrument SSTA anomalies for the equatorial Pacific NINO3 region, Santa Barbara Basin (SBB), and SB across the 1995-1998 interval (including the prominent 1997-98 El Niño event) indicates similar thermal structure at all three locations (Fig. 1), but the SB data exhibits greater ENSO influence than the SBB. Modern analog temperature estimates, using our method on the SBB sediment traps faunas, indicate values that range from 9-21 O C in agreement with instrumental measurements. When the modern analog method is applied to coretop samples from GC-41 and mid-Holocene samples from PC-14, we estimate mid-Holocene temperature of ~10-24 O C, though averaging to be somewhat cooler than the modern coretop value of ~14 O C. Black et al. (2001) suggests that increases in the percent abundance of G. bulloides and G. quinquloba indicate enhanced La Nina-like conditions, while increases in the percent abundance of G. ruber and G. rubescence indicate El Niño-like conditions. A comparison of these four foram species, between GC-41, PC-14, and the SBB sediment trap calibration data, suggests at least part of mid-Holocene in the SB was characterized by more La Niña-like conditions, a trend which is consistent with benthic foram abundances in the same samples. III Conclusions •The high resolution data available from cores MV99-GC-41 and MV99-PC-14 indicate that mid-Holocene conditions in the Soledad Basin consisted of cooler sea surface temperatures and higher levels of productivity. •These conditions are representative of a more La Niña-like climate within the basin during this time period. II Results The relative percent abundances of two cold water species of planktonic foraminifera (G. bulloides and G. quinqueloba) were compared to the percent of two warm water species of planktonic foraminifera (G. ruber and G. rubescence) across the modern coretop (MV99-GC-41) and mid- Holocene downcore (MV99-PC-14) samples. These species were selected by Black et al. (2001) to distinguish between El Niño and non El Niño conditions. When the average “break” between warm and cold species of the modern samples was compared to each mid-Holocene sample, two distinct groups were found, one with more warm water species than the modern values and one with more cold water species than modern values. The group with more cold water species was far more abundant, comprising roughly two-thirds of the mid-Holocene samples thus far analyzed. Please see Figure 3 for a sample by sample analysis. The Modern Analog technique was applied to the coretop and downcore samples using two data sets for correlation, a 1083 sample data set (Ortiz et al. 97; Morey et al, 98?) and the Santa Barbara Basin (SBB) sediment trap data of Black et al. (2001). Average analog sea surfaces temperatures (SSTs) attainted through the 1083 samples data set (Table 1) were compared across the modern samples, the mid- Holocene samples with more warm water species. It was found that the warm water species group had the highest average SST at 15.86 O C, the cold water species group had the lowest average SST at 11.21 O C, and the modern samples had an average SST of 13.61 O C. SeaWiFS chlorophyll data was obtained for the location of each analog found using the 1083 sample data set and used as a proxy for productivity (SeaWiFS Project). This data was averaged across each sample (Table 1) as with the SST estimates and then averaged for the warm water foram species samples, the cold water foram species samples, and the coretop samples. The cold water foram species group had the highest chlorophyll levels (19.08 mg/m 3 ), the warm water foram species group had the lowest levels (15.81 mg/m 3 ), and the modern samples had an intermediate value of 18.77 mg/m 3 . The Santa Barbara Basin sediment trap data was correlated against the Soledad Basin (SB) samples. This comparison indicates if conditions were more like the 97-98 El Niño recorded in these samples or like the non El Niño conditions present before the 97-98 event. While the bulk of the samples were more El Niño-like (and better analogs than found in the 1083 sample data set), it should be noted that the SBB is further north than the SB (see Fig.2) thus analogs showing warm conditions are to be expected. 19.52 19.74 17.09 17.64 19.98 19.16 11.67 16.42 17.26 16.79 19.24 19.74 19.21 17.42 19.96 19.74 19.74 19.74 20.31 19.74 20.14 19.74 19.24 17.23 17.42 16.96 17.23 10.06 19.24 19.16 17.20 19.24 19.02 Ave. SeaWiFS Chla (mg/m3) 0.314 0.2371 0.3207 0.2781 0.2848 0.2619 0.4341 0.2867 0.3353 0.3503 0.259 0.1774 0.2073 0.3288 0.2943 0.3545 0.2593 0.2065 0.6661 0.4422 0.5353 0.2794 0.2562 0.3265 0.2881 0.364 0.3226 0.5419 0.2751 0.265 0.3311 0.3459 0.3133 MA Ave Squared Chord Distance 0.1826 Non 11.52 7.34 ka 690 cm MV99-PC-14 0.2205 Non 10.16 6.08 ka 532 cm MV99-PC-14 0.2318 El Nino 13.52 6.06 ka 528 cm MV99-PC-14 0.1364 El Nino 12.62 6.03 ka 523 cm MV99-PC-14 0.1526 El Nino 12.09 6.00 ka 518 cm MV99-PC-14 0.2411 El Nino 10.44 5.96 ka 513 cm MV99-PC-14 0.4839 Non 24.91 5.94 ka 508 cm MV99-PC-14 0.1893 El Nino 13.46 5.91 ka 503 cm MV99-PC-14 0.2901 El Nino 14.21 5.87 ka 498 cm MV99-PC-14 0.3252 El Nino 14.51 5.73 ka 478 cm MV99-PC-14 0.1923 El Nino 11.63 5.68 ka 473 cm MV99-PC-14 0.2053 El Nino 10.33 5.65 ka 469 cm MV99-PC-14 0.1897 El Nino 9.83 5.59 ka 463 cm MV99-PC-14 0.1859 El Nino 12.33 5.55 ka 458 cm MV99-PC-14 0.1207 Non 10.41 5.46 ka 448 cm MV99-PC-14 0.2315 Non 10.15 5.42 ka 443 cm MV99-PC-14 0.2468 Non 10.22 5.37 ka 438 cm MV99-PC-14 0.2952 Non 10.19 5.29 ka 428 cm MV99-PC-14 0.4838 Non 10.30 5.24 ka 423 cm MV99-PC-14 0.3759 Non 10.22 5.20 ka 418 cm MV99-PC-14 0.5528 Non 10.16 5.15 ka 413 cm MV99-PC-14 0.3055 Non 10.17 5.12 ka 408 cm MV99-PC-14 0.2202 El Nino 11.59 5.08 ka 403 cm MV99-PC-14 0.2395 El Nino 14.00 5.04 ka 398 cm MV99-PC-14 0.1957 El Nino 12.37 4.94 ka 385 cm MV99-PC-14 0.2590 El Nino 16.54 4.91 ka 380 cm MV99-PC-14 0.2182 El Nino 13.83 4.87 ka 375 cm MV99-PC-14 0.4290 El Nino 19.48 4.68 ka 350 cm MV99-PC-14 0.2969 El Nino 11.57 0.62 ka 20 cm MV99-GC-41 0.2205 El Nino 14.82 0.55 ka 15 cm MV99-GC-41 0.3208 El Nino 15.26 0.48 ka 10 cm MV99-GC-41 0.2581 El Nino 11.59 0.41 ka 5 cm MV99-GC-41 0.3412 Non 14.81 0.34 ka 0 cm MV99-GC-41 SBB Ave Squared Chord Distance SBB Trap ENSO Estimate MA SST Estimate (deg C) Age Sample # Core Table 1. Results of the modern analog technique on the 1083 sample set and the Black et al. (2001) sediment traps. (a) Core notes whether the sample originated from the gravity core (GC-41) or the piston core (PC-14). (b) Sample number is depth in core. (c) Age are dates interpolated from a series of 14 C ages (van Geen et al., 2003). (d) MA SST estimate is the average of sea surface temperatures given by the five least dissimilar modern analogs derived from the Modern Analog Technique used to correlate the 1083 sample data set to the Soledad Basin data. (e) MA Ave squared chord distance is the average of dissimilarity coefficients of the top five analogs for each sample taken from the 1083 samples data set. Values greater than 0.2 indicate increasingly poor analogs. (f) Ave. SeaWiFS Chla The locations of analogs obtained for the SST estimates were compared against the SeaWiFS chlorophyll data to be used a a productivity proxy. The values for the five analogs for each samples were averaged. (g) SBB Trap ENSO estimates are the result of using the Modern Analog Technique to correlate the Santa Barbara sediment trap data to the Soledad Basin data. This indicates where the top five least dissimilar analogs were taken from El Niño or Non El Niño conditions. (h) SBB Ave squared chord distance is the average dissimilarity coefficients of the top five analogs for each sample taken from the Santa Barbara Basin sediment trap data set. Values greater than 0.2 indicate increasingly poor analogs. -2 -1 0 1 2 3 4 5 1995 1996 1997 1998 1999 Year SST Anomaly (°C) 5 10 15 20 25 30 Modern Analog Temperature (°C) NCEP Nino3 SSTA (°C) Monthly Smoothed NCEP SSTA @Soledad Basin (°C) Monthly Smoothed NCEP SSTA @ SBB (°C) MA Tmean for SBB Trap Samples of Black et al. (2001) Figure 1. A comparison of NCEP NINO3 SSTA data, monthly smoothed NCEP SSTA data for the Soledad and Santa Barbara Basins, and modern analog temperature estimates for the SBB trap samples of Black et al. (2001). All four sets clearly demonstrate the influence of the 1997-1998 El Niño event. 0% 20% 40% 60% 80% 100% Relative Percent Abundance Black et al. 2001 La Nina El Nino Coretop (GC41) 0.34 ka 0.41 ka 0.48 ka 0.55 ka 0.62 ka Downcore 4.68 ka 4.87 ka 4.91 ka 4.94 ka 5.04 ka 5.08 ka 5.12 ka 5.15 ka 5.20 ka 5.24 ka 5.29 ka 5.37 ka 5.42 ka 5.46 ka 5.55 ka 5.59 ka 5.65 ka 5.68 ka 5.73 ka 5.87 ka 5.91 ka 5.94 ka 5.96 ka 6.00 ka 6.03 ka 6.06 ka 6.08 ka 7.34 ka Comparison of Key Fauna Across Cores % G. bulloides % G. quinqueloba % G. ruber % G. rubescence IV References Black, D., Thunell, R., and Tappa, E., 2001, Planktonic foraminiferal response to the 1997-1998 El Nino: A sediment-trap record from the Santa Barbara Basin, Geology, v. 29, p. 1075-1078 Ortiz, J., and Mix, A., 1997, Comparison of Imbrie-Kipp transfer function and Modern Analog Temperature estimates using sediment trap and coretop foraminiferal faunas, Paleoceanography, v. 12, p. 175-190 SeaWiFS Project, Goddard Spaceflight Center, Data Repository, http://seawifs.gsfc.nasa.gov van Geen et al., 2003, on the preservations of laminations along the western margin of North America, Paleoceanography, in press Figure 3. A comparison of the 4 key species of Black et al. (2001) across the Soledad Basin samples. The black line represents an averaged composition “break” between warm and cool water species. Figure 2. Sea Surface Temperature anomalies of the 1998 La Niña (left) and the 1998 El Niño (right). Noted are the location of the relevant sample locations. ñ Comparison of Ave. An. SSTs 0.00 2.00 4.00 6.00 8.00 10.00 12.00 14.00 16.00 18.00 1 Temperature (deg C) Figure 4. Comparing the average analog SeaWiFS chlorophyll data (left) and average analog SSTs (right) for modern coretop (yellow), warm water foram species group (red), and cold water species group (blue). Comparison of Ave. An. Chloro. 14.00 15.00 16.00 17.00 18.00 19.00 20.00 1 Chlorophyll (mg/m3)
Transcript of MID-HOLOCENE CLIMATE RECONSTRUCTION IN THE SOLEDAD BASIN ...jortiz/home... · The Soledad Basin...
MID-HOLOCENE CLIMATE RECONSTRUCTION IN THEMID-HOLOCENE CLIMATE RECONSTRUCTION IN THESOLEDAD BASIN USING PLANKTIC FORAM ASSEMBLAGESSOLEDAD BASIN USING PLANKTIC FORAM ASSEMBLAGES(Presentation No. 75-25)(Presentation No. 75-25)
WILSBACHER, Matthew C.1, ORTIZ, Joseph1, O'CONNELL, Suzanne2, ZHENG, Yan3, MARCHITTO, Tom4, CARRIQUIRY, Jose5, DEAN, Walter6, and VAN GEEN, Alexander7, (1) Dept. of Geology, Kent StateUniversity, Kent, OH 44242, [email protected], (2) E&ES, Wesleyan Univ, 265 Church St, Middletown, CT 06459, (3) School of Earth and Environmental Sciences, Queens College, C.U.N.Y, 65-30 Kissena Blvd,Flushing, NY 11365, (4) Lamont-Doherty Earth Observatory, Palisades, NY 10964, (5) Instituto de Investigaciones Oceanologicas, Universidad Autonoma de Baja California, Ensenada, Mexico, (6) USGS, EarthSurface Processes, Denver, CO 80225, (7) LDEO, Palisades, NY 10964
I AbstractThe instrumental climate record for the subtropical Pacific is useful for reconstructinginterannual climate variability, though it is limited by its short-term duration. Climateproxies from high-resolution sites can be used in extending this record to geologic timescales, but only if the proxies are properly calibrated. The Soledad Basin (SB) off thecoast of Baja, California (25O12’ N, 112O 43’ W) is a viable locale for constructing suchproxies due to its high sedimentation rate, providing a temporal resolution of ~10yr/cm. Here, we present a pilot study of modern analog temperature estimates basedon planktic foraminiferal faunal assemblages from SB gravity (MV99-GC-41) andpiston (MV99-PC-14) cores. The goal of this study is to explore whether productivity inthe SB during the mid-Holocene, a period of strong summer insulation, was higher orlower than modern values. These faunal temperature estimates are calibrated againsta 1083 sample data set (Ortiz et al., 1997) and 1995-1998 Santa Barbara Basin(34O14’N, 120O02’W) sediment trap faunas from Black et al. (2001). Comparing NCEPinstrument SSTA anomalies for the equatorial Pacific NINO3 region, Santa BarbaraBasin (SBB), and SB across the 1995-1998 interval (including the prominent 1997-98El Niño event) indicates similar thermal structure at all three locations (Fig. 1), but theSB data exhibits greater ENSO influence than the SBB. Modern analog temperatureestimates, using our method on the SBB sediment traps faunas, indicate values thatrange from 9-21OC in agreement with instrumental measurements. When the modernanalog method is applied to coretop samples from GC-41 and mid-Holocene samplesfrom PC-14, we estimate mid-Holocene temperature of ~10-24OC, though averagingto be somewhat cooler than the modern coretop value of ~14OC. Black et al. (2001)suggests that increases in the percent abundance of G. bulloides and G. quinqulobaindicate enhanced La Nina-like conditions, while increases in the percent abundance ofG. ruber and G. rubescence indicate El Niño-like conditions. A comparison of thesefour foram species, between GC-41, PC-14, and the SBB sediment trap calibrationdata, suggests at least part of mid-Holocene in the SB was characterized by more LaNiña-like conditions, a trend which is consistent with benthic foram abundances in thesame samples.
III Conclusions•The high resolution data available from cores MV99-GC-41 and MV99-PC-14indicate that mid-Holocene conditions in the Soledad Basin consisted of coolersea surface temperatures and higher levels of productivity.
•These conditions are representative of a more La Niña-like climate within thebasin during this time period.
II Results
The relative percent abundances of two cold water species of planktonicforaminifera (G. bulloides and G. quinqueloba) were compared to thepercent of two warm water species of planktonic foraminifera (G. ruberand G. rubescence) across the modern coretop (MV99-GC-41) and mid-Holocene downcore (MV99-PC-14) samples. These species wereselected by Black et al. (2001) to distinguish between El Niño and nonEl Niño conditions. When the average “break” between warm and coldspecies of the modern samples was compared to each mid-Holocenesample, two distinct groups were found, one with more warm waterspecies than the modern values and one with more cold water speciesthan modern values. The group with more cold water species was farmore abundant, comprising roughly two-thirds of the mid-Holocenesamples thus far analyzed. Please see Figure 3 for a sample by sampleanalysis.
The Modern Analog technique was applied to the coretop and downcoresamples using two data sets for correlation, a 1083 sample data set(Ortiz et al. 97; Morey et al, 98?) and the Santa Barbara Basin (SBB)sediment trap data of Black et al. (2001). Average analog sea surfacestemperatures (SSTs) attainted through the 1083 samples data set(Table 1) were compared across the modern samples, the mid-Holocene samples with more warm water species. It was found that thewarm water species group had the highest average SST at 15.86OC, thecold water species group had the lowest average SST at 11.21OC, andthe modern samples had an average SST of 13.61OC.
SeaWiFS chlorophyll data was obtained for the location of each analogfound using the 1083 sample data set and used as a proxy forproductivity (SeaWiFS Project). This data was averaged across eachsample (Table 1) as with the SST estimates and then averaged for thewarm water foram species samples, the cold water foram speciessamples, and the coretop samples. The cold water foram species grouphad the highest chlorophyll levels (19.08 mg/m3), the warm water foramspecies group had the lowest levels (15.81 mg/m3), and the modernsamples had an intermediate value of 18.77 mg/m3.
The Santa Barbara Basin sediment trap data was correlated against theSoledad Basin (SB) samples. This comparison indicates if conditionswere more like the 97-98 El Niño recorded in these samples or like thenon El Niño conditions present before the 97-98 event. While the bulk ofthe samples were more El Niño-like (and better analogs than found inthe 1083 sample data set), it should be noted that the SBB is furthernorth than the SB (see Fig.2) thus analogs showing warm conditions areto be expected.
19.52
19.74
17.09
17.64
19.98
19.16
11.67
16.42
17.26
16.79
19.24
19.74
19.21
17.42
19.96
19.74
19.74
19.74
20.31
19.74
20.14
19.74
19.24
17.23
17.42
16.96
17.23
10.06
19.24
19.16
17.20
19.24
19.02
Ave.SeaWiFS
Chla(mg/m3)
0.314
0.2371
0.3207
0.2781
0.2848
0.2619
0.4341
0.2867
0.3353
0.3503
0.259
0.1774
0.2073
0.3288
0.2943
0.3545
0.2593
0.2065
0.6661
0.4422
0.5353
0.2794
0.2562
0.3265
0.2881
0.364
0.3226
0.5419
0.2751
0.265
0.3311
0.3459
0.3133
MA AveSquaredChord
Distance
0.1826Non11.527.34 ka690 cmMV99-PC-14
0.2205Non10.166.08 ka532 cmMV99-PC-14
0.2318El Nino13.526.06 ka528 cmMV99-PC-14
0.1364El Nino12.626.03 ka523 cmMV99-PC-14
0.1526El Nino12.096.00 ka518 cmMV99-PC-14
0.2411El Nino10.445.96 ka513 cmMV99-PC-14
0.4839Non24.915.94 ka508 cmMV99-PC-14
0.1893El Nino13.465.91 ka503 cmMV99-PC-14
0.2901El Nino14.215.87 ka498 cmMV99-PC-14
0.3252El Nino14.515.73 ka478 cmMV99-PC-14
0.1923El Nino11.635.68 ka473 cmMV99-PC-14
0.2053El Nino10.335.65 ka469 cmMV99-PC-14
0.1897El Nino9.835.59 ka463 cmMV99-PC-14
0.1859El Nino12.335.55 ka458 cmMV99-PC-14
0.1207Non10.415.46 ka448 cmMV99-PC-14
0.2315Non10.155.42 ka443 cmMV99-PC-14
0.2468Non10.225.37 ka438 cmMV99-PC-14
0.2952Non10.195.29 ka428 cmMV99-PC-14
0.4838Non10.305.24 ka423 cmMV99-PC-14
0.3759Non10.225.20 ka418 cmMV99-PC-14
0.5528Non10.165.15 ka413 cmMV99-PC-14
0.3055Non10.175.12 ka408 cmMV99-PC-14
0.2202El Nino11.595.08 ka403 cmMV99-PC-14
0.2395El Nino14.005.04 ka398 cmMV99-PC-14
0.1957El Nino12.374.94 ka385 cmMV99-PC-14
0.2590El Nino16.544.91 ka380 cmMV99-PC-14
0.2182El Nino13.834.87 ka375 cmMV99-PC-14
0.4290El Nino19.484.68 ka350 cmMV99-PC-14
0.2969El Nino11.570.62 ka20 cmMV99-GC-41
0.2205El Nino14.820.55 ka15 cmMV99-GC-41
0.3208El Nino15.260.48 ka10 cmMV99-GC-41
0.2581El Nino11.590.41 ka5 cmMV99-GC-41
0.3412Non14.810.34 ka0 cmMV99-GC-41
SBB AveSquaredChord
Distance
SBB TrapENSO
Estimate
MA SSTEstimate(deg C)Age
Sample#Core
Table 1. Results of the modern analog technique on the 1083 sample set andthe Black et al. (2001) sediment traps.
(a) Core notes whether the sample originated from the gravity core (GC-41) or thepiston core (PC-14). (b) Sample number is depth in core. (c) Age are datesinterpolated from a series of 14C ages (van Geen et al., 2003). (d) MA SSTestimate is the average of sea surface temperatures given by the five leastdissimilar modern analogs derived from the Modern Analog Technique used tocorrelate the 1083 sample data set to the Soledad Basin data. (e) MA Avesquared chord distance is the average of dissimilarity coefficients of the top fiveanalogs for each sample taken from the 1083 samples data set. Values greaterthan 0.2 indicate increasingly poor analogs. (f) Ave. SeaWiFS Chla The locationsof analogs obtained for the SST estimates were compared against the SeaWiFSchlorophyll data to be used a a productivity proxy. The values for the five analogsfor each samples were averaged. (g) SBB Trap ENSO estimates are the result ofusing the Modern Analog Technique to correlate the Santa Barbara sediment trapdata to the Soledad Basin data. This indicates where the top five least dissimilaranalogs were taken from El Niño or Non El Niño conditions. (h) SBB Ave squaredchord distance is the average dissimilarity coefficients of the top five analogs foreach sample taken from the Santa Barbara Basin sediment trap data set. Valuesgreater than 0.2 indicate increasingly poor analogs.
-2
-1
0
1
2
3
4
5
1995 1996 1997 1998 1999Year
SS
T A
no
maly
(°C
)
5
10
15
20
25
30
Mo
dern
An
alo
g T
em
pera
ture
(°C
)
NCEP Nino3 SSTA (°C)
Monthly Smoothed NCEP SSTA@Soledad Basin (°C)
Monthly Smoothed NCEP SSTA @SBB (°C)
MA Tmean for SBB Trap Samplesof Black et al. (2001)
Figure 1. A comparison of NCEP NINO3 SSTA data, monthly smoothed NCEPSSTA data for the Soledad and Santa Barbara Basins, and modern analogtemperature estimates for the SBB trap samples of Black et al. (2001). All four setsclearly demonstrate the influence of the 1997-1998 El Niño event.
0% 20% 40% 60% 80% 100%
Relative Percent Abundance
Black et al. 2001La NinaEl Nino
Coretop (GC41)0.34 ka0.41 ka0.48 ka0.55 ka0.62 ka
Downcore4.68 ka4.87 ka4.91 ka4.94 ka5.04 ka5.08 ka5.12 ka5.15 ka5.20 ka5.24 ka5.29 ka5.37 ka5.42 ka5.46 ka5.55 ka5.59 ka5.65 ka5.68 ka5.73 ka5.87 ka5.91 ka5.94 ka5.96 ka6.00 ka6.03 ka6.06 ka6.08 ka7.34 ka
Comparison of Key Fauna Across Cores% G. bulloides
% G. quinqueloba
% G. ruber
% G. rubescence
IV ReferencesBlack, D., Thunell, R., and Tappa, E., 2001, Planktonic foraminiferal response to the1997-1998 El Nino: A sediment-trap record from the Santa Barbara Basin, Geology,v. 29, p. 1075-1078
Ortiz, J., and Mix, A., 1997, Comparison of Imbrie-Kipp transfer function and ModernAnalog Temperature estimates using sediment trap and coretop foraminiferal faunas,Paleoceanography, v. 12, p. 175-190
SeaWiFS Project, Goddard Spaceflight Center, Data Repository,http://seawifs.gsfc.nasa.gov
van Geen et al., 2003, on the preservations of laminations along the western marginof North America, Paleoceanography, in press
Figure 3. A comparison of the 4 key species of Black et al. (2001)across the Soledad Basin samples. The black line represents anaveraged composition “break” between warm and cool waterspecies.
Figure 2. Sea Surface Temperatureanomalies of the 1998 La Niña (left) and the1998 El Niño (right). Noted are the location ofthe relevant sample locations.
ñ
Comparison of Ave. An. SSTs
0.00
2.00
4.00
6.00
8.00
10.00
12.00
14.00
16.00
18.00
1
Tem
pera
ture
(d
eg
C)
Figure 4. Comparing the average analog SeaWiFS chlorophyll data(left) and average analog SSTs (right) for modern coretop (yellow),warm water foram species group (red), and cold water species group(blue).
Comparison of Ave. An. Chloro.
14.00
15.00
16.00
17.00
18.00
19.00
20.00
1
Chlo
rophyl
l (m
g/m
3)
