Human responses to Middle Holocene climate change on California's Channel Islands

Variable name changed from ageType to type during update from DKs csv files.

Variable name changed from age14Cuncertainty to 1SD during update from DKs csv files.

Variable name changed from age14C to age during update from DKs csv files.

Date AA-7199 was 121% modern carbon (post-bomb).

precipitation (M2Leedqkm0xP): paleoData_notes: 'unpublished precip' has been replaced by ''

Holocene Paleoecology of an Estuary on Santa Rosa Island, California

North America>United States Of America>California

Small estuarine marsh. Physiography: Santa Rosa Island. Surrounding vegetation: coastal marsh and grassland.

GoE values close to one would indicate La Nia-like conditions, while values closed to zero would imply strong El Nio-like conditions.

"GoE values close to one would indicate La Niña-like conditions, while values closed to zero would imply strong El Niño-like conditions."

High GoF values indicate shallow nutricline, thus strong upwelling and reduced water column stratification, while low values indicate a deeper nutricline, weak upwelling and deep stratification

"High GoF values indicate shallow nutricline, thus strong upwelling and reduced water column stratification, while low values indicate a deeper nutricline, weak upwelling and deep stratification"

pub1_author: 'list(list(name = "Staines-Urías, Francisca"), list(name = "González-Yajimovich, Oscar"), list(name = "Beaufort, Luc"))' has been replaced by 'Staines-Urias, Francisca'

This marks the creation of the changelog, and marks the status of this dataset as of mid 2020

<jats:p>Nannofossil assemblages from core MD02-2510 provide a ~ 22 ka record of past oceanographic variability in Alfonso Basin (Gulf of California, east subtropical Pacific). In this area, environmental conditions depend on a monsoonal system heavily influenced by changes in the location of the ITCZ and nearby atmospheric pressure centers. To reconstruct nutricline depth and ENSO-like variability, two ecological indexes were calculated based on the relative abundance of the three dominant coccolith species. The late glacial period is characterized by intensified wind-driven upwelling, high primary productivity and La Niña-like conditions. An environmental shift occurs during the glacial–interglacial transition, El Niño-like conditions intensify, nutricline deepens and surface productivity declines. The late Holocene is characterized by a persistent increase in nutricline depth and dominance of El Niño-like conditions. The fluctuations in the composition of the coccolith assemblages can be related to orbital-scale fluctuations in the average position of the ITCZ. However, while the ENSO-like signal that overprints the record varies in response to orbital forcing, on suborbital time scales the relation between ENSO-like conditions and the average position of the ITCZ and the North Pacific High changes, suggesting that the development of persistent El Niño-like conditions is strongly dependent on the specific climatic background.</jats:p>