geochemical reconstruction of pacific decadal variability from the eastern north pacific during the holocene determining climate variations over the holocene requires high resolution records with well developed age models a 40 m long marine sediment core raised from effingham inlet an anoxic fjord on the west coast of vancouver island british columbia canada yields such a record forty six 14c accelerator mass spectrometry ams dates determined from terrestrial plant material form the age model downcore sampling at both 5 cm 20 year and 1 5 cm 7 year resolution indicates that high frequency oceanographic variability has prevailed at this site over the last 10 000 years spectral analysis of wt opal a proxy for diatom productivity in the basin reveals the bidecadal and pentadecadal periods of the pacific decadal oscillation pdo north pacific index npi that are related to changes in the strength of the aleutian low coherence analysis between the effingham inlet data and 18o records from jellybean lake a high elevation site in southwest yukon indicates regional coherence at periods of 45 7

late holocene variability in pelagic fish scales and dinoflagellate cysts along the west coast of vancouver island ne pacific ocean fish stocks and dinoflagellates are essential components of the marine food chain sediment cores from a predominantly anoxic basin in effingham inlet vancouver island british columbia archive a late holocene 500 5300 years bp record of paleoproductivity in the north american coastal upwelling domain cud we present evidence that late holocene changes in the dinoflagellate cyst assemblages sedimentary record and fish stocks in the northeastern pacific ocean fluctuated at least partially in accordance with regional and global climate cycles principal components analysis pca and trend wavelet and spectral analyses were used to identify relationships cycles and trends in sediment grey scale values and the abundances of fish scales and dinoflagellate cysts on centennial to millennial time scales most observed cycles fluctuated in intensity over time particularly following transition of the regional climate to a higher rainfall phase that impacted coastal oceanic dynamics 3400f150 years ago correlation of the marine paleoproductivity records observed in effingham inlet with solar influenced climate proxy cycles observed in the north atlantic region indicates that solar forcing at different scales might have influenced the climate in the northeast pacific as well in particular an 1100 to 1400 year cycle in regional climate is well represented in the fish productivity proxy and sedimentological record it was also observed that colder water high productivity selenopemphix nephroides and anchovydominated banchovy regimeq ecosystems alternate with warmer water herring dominated bherring regimeq ecosystems at millennial time scales the fish scale record preserved in effingham inlet indicates that the ne pacific is now in transition from an danchovy t to a dherringt dominated regime d 2005 elsevier b v all rights reserved

climate change and decadal to centennial scale periodicities recorded in a late holocene ne pacific marine record examining the role of solar forcing abstract we present a decadal scale late holocene climate record based on diatoms biogenic silica and grain size from a 12 m sediment core vec02a04 obtained from frederick sound in the seymour belize inlet complex of british columbia canada sediments are characterized by graded massive and laminated intervals laminated intervals are most common between c 2948 2708 cal yr bp and c 1992 1727 cal yr bp increased preservation of laminated sediments and diatom assemblage changes at this time suggest that climate became moderately drier and cooler relative to the preceding and succeeding intervals spectral and wavelet analyses are used to test for statistically significant periodicities in time series of proxies of primary production total diatom abundance biogenic silica and hydrology grain size preserved in the frederick sound record periodicities of c 42 53 60 70 82 89 241 243 and 380 yrs are present results are compared to reconstructed sunspot number data of solanki et al 2004 using cross wavelet transform to evaluate the role of solar forcing on ne pacific climate significant common power of periodicities between c 42 60 70 89 241 243 and of 380 yrs occur suggesting that celestial forcing impacted late holocene climate at frederick sound replication of the c 241 243 yr periodicity in sunspot time series is most pronounced between c 2900 cal yr bp and c 2000 cal yr bp broadly correlative to the timing of maximum preservation of laminated sedimentary successions and diatom assemblage changes high solar activity at the suess de vries band may have been manifested as a prolonged westward shift and or weakening of the aleutian low in the mid late holocene which would have diverted fewer north pacific storms and resulted in the relatively dry conditions reconstructed for the seymour belize inlet complex

high resolution climatic evolution of coastal northern california during the past 16 000 years holocene and latest pleistocene oceanographic conditions and the coastal climate of northern california have varied greatly based upon high resolution studies ca every 100 years of diatoms alkenones pollen caco 3 and total organic carbon at ocean drilling program odp site 1019 41 682 n 124 930 w 980 m water depth marine climate proxies alkenone sea surface temperatures ssts and caco 3 behaved remarkably like the greenland ice sheet project gisp 2 oxygen isotope record during the balling allerod younger dryas yd and early part of the holocene during the yd alkenone ssts decreased by 3 c below mean bolling allerod and holocene ssts the early holocene ca 11 6 to 8 2 ka was a time of generally warm conditions and moderate caco 3 content generally 4 the middle part of the holocene ca 8 2 to 3 2 ka was marked by alkenone ssts that were consistently 1 2 c cooler than either the earlier or later parts of the holocene by greatly reduced numbers of the gyre diatom pseudoeunotia doliolus 10 and by a permanent drop in caco 3 to 3 starting at ca 5 2 ka coastal redwood and alder began a steady rise arguing for increasing effective moisture and the development of the north coast temperate rain forest at ca 3 2 ka a permanent ca 1 c increase in alkenone sst and a threefold increase in p doliolus signaled a warming of fall and winter ssts intensified higher amplitude and more frequent cycles of pine pollen alternating with increased alder and redwood pollen are evidence that rapid changes in effective moisture and seasonal temperature enhanced el nino southern oscillation enso cycles have characterized the site 1019 record since about 3 5 ka

a holocene record of marine fish remains from the northeastern pacific abstract ocean drilling program leg 169s retrieved a complete holocene sequence from saanich inlet british columbia canada fish and diatom remains were extracted from sediments at site 1034 very small fish bones teeth and scales were ubiquitous except in the lowermost glaciomarine clays scales degraded with depth in the identifiable fraction pacific herring were the most abundant with pacific hake and cartilaginous fish yielding significant fractions fish remains appear just before 12 000 bp but greatest diversity does not occur until about 6500 bp a smoothed abundance curve highlights two periods of maximal abundance at about 1500 and 6500 bp abundances in the last 1000 years are lower than the rest of the record a correlation with abundances of seven phytoplankton taxa is significant diatoms explain about a third of the variance this study demonstrates the use of fish and diatoms from the same paleosedimentary matrix to examine millennia scale correlations between primary and tertiary production

neoglaciation in the southern coast mountains of british columbia chronology prior to the late neoglacial maximum moraine stratigraphy and morphology radiocarbon dates from klinaklini franklin tiedemann gilbert and bridge glaciers and related information from elsewhere in the coast mountains are used to construct a chronology for glacier fluctuations the garibaldi phase of glacier expansion 6000 5000 14c years bp at the end of the early holocene xerothermic interval is indicated by overridden tree stumps the mid neoglacial tiedemann advance 3300 1900 14c years bp is represented by moraines till and meltwater sediments at three glaciers but only tiedemann glacier attained its greatest holocene extent at this time late neoglacial expansion commenced before 900 14c years bp and continued without notable interruption until glaciers achieved their maximum post pleistocene expansion during the eighteenth and nineteenth centuries evidence for the garibaldi and tiedemann events is scarce within the coast mountains because of the more extensive late neoglacial advance however correlative advances have been

siliceous microfossil record of late holocene oceanography and climate along the west coast of vancouver island british columbia canada diatoms silicoflagellates and biogenic silica bsi were analyzed from two piston cores recovered from effingham inlet british columbia relatively productive marine conditions from 4850 to 4000 cal yr bp were followed by a transition to the modern ocean climate regime marked by a decreased siliceous microfossil production since 2800 cal yr bp this change in the northeast pacific climate was characterized by an apparent cooling associated with higher rainfall and lower light levels the reduced abundance of most spring summer bloom diatom taxa skeletonema thalassiosira chaetoceros was coupled with a decreased abundance of diatoms normally associated with incursions of offshore water into coastal inlets this pattern reflected a weaker summer upwelling along vancouver island associated with the insolation related increase in the strength of the aleutian low and a weakened north pacific high after ca 2800 cal yr bp diatom assemblages also indicated more frequent periods of relatively low spring summer surface water salinity and a disruption of the typical bloom sequence indicative of increased climatic variability a period of warmer and drier climate conditions and possibly increased coastal upwelling offshore occurred ca 1450 1050 cal yr bp the most recent 500 yr are marked by reduced diatom production and the appearance of three distinct diatom biomarkers in the stratigraphic record rhizosolenia setigera ca ad 1940 minidiscus chilensis ca ad 1860 thalassionema nitzschioides morphotype a ca ad 1550 the oceanographic changes recorded in effingham inlet are correlative with other marine and terrestrial paleoenvironmental records in the northeast pacific ocean

seasonal associations of phytoplankton and planktic foraminifera in an upwelling region and their contribution to the seafloor abstract seasonal occurrences of both phytoplankton and zooplankton are closely associated with upwelling and stabilization in waters overlying the san pedro basin this region is situated within the southern california bight and is affected by variations in the general southward flowing california current and variable intrusion of oceanic waters increased northerly wind stress in spring and early summer results in upwelling of deeper nutrient rich waters into the photic zone a seven month time series sediment trap experiment revealed clear patterns in seasonal succession of both phytoplankton and planktic foraminifera several distinct high and low flux periods occurred over the study period some of which can be related to rapid changes in the hydrographic environment caused by upwelling and subsequent surface water stratification factor analysis of relative abundances of combined phytoplankton and foraminiferal taxa defines seven assemblages reflecting seven stages of production which range in duration from two to five weeks factor scores describe phytoplankton and foraminiferal taxa indicative of specific production stages periods of high flux of the more abundant diatoms and planktic foraminifera also illustrate preferred production stages and compare well with percentage based results a comparison of the sediment trap assemblage with local sediment from an oxygenated portion of the basin suggests that long term phytoplankton accumulation in this region is dominated by taxa associated with winter bloom and post upwelling bloom production implying that brief but massive episodic events overwhelm and dominate the annually averaged diatom species assemblage found in the sediments foraminifera however are modified by dissolution to the extent that the high production periods of late spring and during upwelling are poorly represented rather species indicative of early spring and post upwelling conditions dominate the planktic foraminiferal sedimentary assemblage

geochemical and diatom signatures of bottom water renewal events in effingham inlet british columbia canada abstract sediments from effingham inlet vancouver island british columbia hold a valuable high resolution holocene record of paleoclimatic and paleoceanographic conditions in the northeast pacific ocean accurate interpretation of this record requires that the depositional environment be well understood in order to assess deposition within the fjord over the last 1500 years two cores a soutar box core and a kasten core were analyzed for fossil diatoms and biogeochemical properties the cores contain varved sequences intercalated with homogeneous mud layers and a seismite we show that homogeneous mud units related to periods of bottom water renewal are geochemically distinct from the seismite and that these bottom renewal events are favored when brackish rather than marine surface water conditions are present the seismite deposited in ad 1946 has lower opal and higher organic carbon concentrations and higher organic carbon nitrogen ratios reflecting greater terrestrial material input in contrast homogeneous mud units are marked by a lower organic c n and more isotopically heavy 13 c values suggesting a stronger marine influence major metals and trace element data also confirm that the source material of these units differs from that of the ad 1946 seismite fossil diatom assemblages within the homogeneous mud units are characterized by a decreased abundance of typical marine spring bloom taxa skeletonema costatum chaetoceros spp thalassiosira spp coupled with an increased abundance of the brackish water taxon cyclotella choctawhatcheeana reduced surface salinity enhances stratification of the water column which in turn favors an intensified two layer estuarine exchange across the shallow sills and associated bottom water renewal the homogeneous mud units are produced through transport of sediment into the fjord coupled with a reworking of the upper layers of the sediment column therefore these units represent a recorder of past changes in regional oceanography and climate

distinct modes of bidecadal and multidecadal variability in a climate reconstruction of the last centuries from a south pacific coral the rarotonga coral sr ca time series linsley et al in science 290 1145 1148 2000 provides a near monthly resolved proxy record of south pacific climate variability over the last 300 years here we show that two distinct interdecadal quasi periodic time components with periods of 80 and 25 years can be identified in this time series by singular spectrum analysis their associated spatial patterns in the global sea surface temperature sst field show notable differences whereas the multidecadal component is associated with a global sst pattern that was recently associated with solar forcing on multidecadal timescales the bidecadal component is associated with a well known pattern of pacific decadal to interdecadal sst variability

late holocene paleofish populations in effingham inlet british columbia canada abstract paleontological studies of fish remains in laminated sediments provide a proxy relationship between fish populations and ocean climate this study examines climate variability from approximately 500 y b p to 4000 y b p as recorded in fish remain abundances primarily scales collected from laminated sediments within effingham inlet on the west coast of vancouver island british columbia the study also discusses technical issues involving fish remains from laminated sediments including sampling resolution sediment volume identification of remains and appropriate abundance considerations the dominant species in the assemblage include northern anchovy and pacific herring with lesser percentage abundances from rockfish hake elasmobranches and surfperch the data indicate that northern anchovy experienced a shift in scale deposition abundance at approximately 2800 y b p with not only a greater total abundance but also a greater consistency of deposition with time pacific herring underwent cyclical deposition that changed little through time statistical analysis reveals that none of these species is directly responding to climatic signals as indicated in the lithological and palynological record but that this could have been partially due to the sampling resolution of the piston core analysis indicates a lack of correlation between the two dominant species as might be expected on the basis of their opposing lifestyle strategies with respect to sea surface temperatures with appropriate sampling strategies paleohistorical fish remains from laminated sediments reflect changes in population structure and behaviour for some species illustrate basic secondary trophic information and provide potential clues to basin scale oceanographic climatological variability

fracture orientation determination in sedimentary rocks using multicomponent ground penetrating radar measurements the resolution provided by conventional single component gpr surveys is not always sufficient to determine fracture location and orientation multicomponent measurements can help in these determinations through phase and amplitude analysis the phase of a radar wavelet is altered as it passes through a fracture the amount of phase change depends upon the relative orientation of the fracture and the direction of the incident electric field if the phase change is measured for a known orientation of the antennas then the strike of the fracture can be determined for our purpose multicomponent means repeating measurements at the same location for different antenna configurations and orientations

fire and vegetation history from the coastal rain forest of the western oregon coast range high resolution charcoal and pollen analyses were used to reconstruct a 4600 yr long history of fire and vegetation near taylor lake in the wettest forests of coastal oregon today fires in these forests are rare because the season of ignition does not coincide with months of dry fuels from ca 4600 to 2700 cal yr b p fire episodes occurred at intervals of 140 30 yr while forest vegetation was dominated by disturbance adapted taxa such as alnus rubra from ca 2700 cal yr b p to the present fire episodes have become less common occurring at intervals of 240 30 yr and firesensitive forest taxa such as tsuga heterophylla and picea sitchensis have become more prominent fire occurrence during the midholocene was similar to that of the more xeric forests in the eastern coast range and suggests that summer drought was widespread after ca 2700 cal yr b p a decrease in fire episode frequency suggests that cooler conditions and possibly increased summer fog allowed the establishment of present day picea sitchensis forests within the watershed these results provide evidence that fire has been an important disturbance agent in the coast range of oregon and variations in fire frequency and climate have led to the establishment of present day forests c 2002 university of washington

a holocene record of diatom and silicoflagellate microfossils in sediments of saanich inlet odp leg 169s odp leg 169s laminated sediment cores provided a unique opportunity to examine changes in the siliceous phytoplankton community of saanich inlet these laminated sediments are rich in diatom and silicoflagellate remains as a result of the inlet s high production and excellent preservation our results suggest that species composition and abundance of diatoms and silicoflagellates in the inlet have changed very little since the inlet s formation carbon and opal data indicate an increase in primary productivity with time which is not apparent in the fossil data however the discrepancy between data sets may be due to changes in grazer activity which could have reduced the number of identifiable fossils individual species were useful for identifying changes in the inlet some planktonic diatoms suggest that nutrient supply was highest in the early mid holocene increases in the abundance of a partially benthic diatom paralia sulcata follow variations in sea level and availability of benthic habitat in the inlet a large peak of the silicoflagellate dictyocha fibula corresponds to a catastrophic flood event in the early holocene which probably washed terrestrial material and low salinity water from the british columbia mainland into saanich inlet fossil data were also analyzed to infer past changes in the environment using a weighted averaging calibration and regression technique these data suggest that only minor variations in sea surface temperature have occurred

a new high resolution radiocarbon bayesian age model of the holocene and late pleistocene from core md02 2494 and others effingham inlet british columbia canada with an application to the paleoseismic event chronology of the cascadia subduction zone annually laminated sediments from the anoxic inner basin of effingham inlet pacific coast of vancouver island british columbia canada yield a high resolution 42 m paleoenvironmental record from the present to about 14 ka 14c bp 17 ka cal bp a new age model based on 68 radiocarbon dates from twigs and small plant material from the 40 m core md02 2494 and 2 m freeze cores from the surface is anchored by the mazama ash and varve counting a poisson process sedimentation model is used applying a new method to determine the poisson k value giving a realistic age model compatible with the multi proxy core data twenty one seismites which are lithofacies in the effingham cores that may be representative of seismically triggered mass wasting events are identified and dated precisely then compared with the chronology of the deep sea turbidite record farther south in the cascadia subduction zone csz to determine if regional sediment disturbances can be identified with 16 proposed correlations

a high resolution marine palynological record from the central mainland coast of british columbia canada evidence for a mid late holocene dry climate interval abstract sediments collected in a 12 m long core vec02a04 obtained from frederick sound in the seymour belize inlet complex of british columbia were deposited between ca 4540 cal yr bp and ca 1090 cal yr bp in primarily dysoxic conditions the sediments are characterized by alternating intervals of fine grained massive and laminated units laminated sediments consist of light coloured diatom rich layers deposited during summer and dark coloured mineral rich layers deposited during winter laminated sediments are most common in portions of the core deposited between ca 2840 cal yr bp and ca 1820 cal yr bp and correspond to a decline in the relative abundance and pollen accumulation rate of cupressaceae pollen between ca 3190 cal yr bp and ca 2250 cal yr bp the preservation of laminated units and decline of cupressaceae pollen at this time suggest that a drier and possibly cooler climate punctuated otherwise wet and temperate late holocene conditions in the seymour belize inlet complex we correlate the occurrence of the mid late holocene dry climate interval documented in frederick sound to dynamics in the relative position and intensity of the aleutian low pressure system and suggest that climate change associated with dynamics of this semi permanent air mass affected primary productivity and vegetation of the seymour belize inlet complex

a 6000 yr varve record of holocene climate in saanich inlet british columbia from digital sediment colour analysis of odp leg 169s cores abstract high resolution grey value time series were extracted from digital images of varved sediments in saanich inlet british columbia odp sites 1033 and 1034 results allowed reconstruction of a 6000 yr long record with annual resolution composite records were compiled for sites 1033 and 1034 by correlation of massive beds which represent gravity flows and of characteristic features in the varve patterns the varve count age scale was calibrated with published radiocarbon ages results demonstrate that the odp leg 169s record is virtually complete saanich inlet varve record has the potential to provide a high resolution climate record temporal variation in varve thickness is interpreted to reflect regional precipitation history with thick varves representing wet conditions long term changes in varve thickness during the past 6000 yr coincide with known changes in global climate but without an obvious one to one correlation between wet dry in saanich inlet and warm cold periods elsewhere varve thickness indicates that the climate around saanich inlet was wet from the start of the varved sequence at 6000 to 3250 yr bp between 2100 and 1750 yr bp roman warm period and from 500 yr bp onward including during little ice age

the 2011 tohoku tsunami generated major environmental changes in a distal canadian fjord 1 tsunamis triggered by powerful earthquakes cause extensive damage and loss of life within many regions of the world ocean although coastal inundation from major tsunamis is becoming increasingly well understood we know little about the broader aspects of such events on distal marine systems here we use time series from moored oceanic sensors to show that the tohoku tsunami generated by the magnitude 9 0 earthquake off eastern japan in march 2011 caused days of surge like currents and turbulent mixing in the inner basin of an anoxic canadian fjord located over 7000 km from the seafloor rupture zone mixing combined with the inflow of more oxygen rich water from the adjoining outer basin led to abrupt changes in the hydrodynamics bottom sedimentation and zooplankton behavior in the basin these findings help define mechanisms by which major transoceanic tsunamis can significantly alter coastal marine environments located far from the source area

a record of past ocean atmosphere radiocarbon differences from the northeast pacific a record of the 14c age differences between atmosphere and the mixed layer of the northeast pacific ocean was obtained from 58 radiocarbon measurements on shells and associated wood from coastal sediments in british columbia this series of mixed layer reservoir ages spans the holocene and extends into the period of the younger dryas cold event in the north atlantic and surrounding regions the data reflect the extent of upwelling in the northeast pacific and thus constrain models of carbon cycling and ocean circulation most of the reservoir ages are only slightly less than than the present preindustrial value of about 800 years and may be identical when probable sampling errors are taken into account either the north pacific reached a state close to its present mode of circulation at or before the end of the younger dryas or a different circulation fortuitously produced a similar reservoir age our results support the hypothesis that slow changes in atmospheric radiocarbon concentrations over the holocene arose from 14c production rate changes data corresponding to a radiocarbon age of around 6400 years b p give a reservoir age of 1200 years if this result is confirmed it indicates a much greater variability for the holocene ocean circulation than was previously believed possible

distribution of diatom surface sediment assemblages within effingham inlet a temperate fjord on the west coast of vancouver island canada abstract twenty nine surface sediment samples from effingham inlet a small fjord on the west coast of vancouver island british columbia were analyzed for diatoms this fjord has been selected for paleoceanographic investigation due to the presence of laminated sediments resulting from the dysoxic to anoxic bottom water conditions in the inner and outer basins of the inlet distributional patterns of the diatom microflora reflected proximity to littoral regions phytoplankton production and marine influence from outside the fjord principal components and cluster analyses of the microflora established four diatom assemblages with a clear separation between the inner and outer basin diatom floras inner basin stations were characterized by elevated absolute abundance with assemblages dominated by spring early summer bloom taxa including skeletonema costatum thalassiosira nordenskioeldii and thalassiosira pacifica chaetoceros spp resting spores were abundant throughout effingham inlet with the exception of the stations closest to the fjord head stations located in the outer basin and towards the fjord mouth had relatively lower absolute abundance yet showed a higher relative and absolute abundance of thalassionema nitzschioides rhizosolenia setigera coscinodiscus radiatus ditylum brightwellii odontella longicruris and paralia sulcata in relation to the inner basin many of these latter taxa are often associated with late summer and autumn conditions in fjords along coastal british columbia oceanographic data for effingham inlet suggest that increased offshore penetration is more likely to occur from summer to early fall with a more restricted offshore influence in the inner basin diatom surface sediment assemblages in effingham inlet appear to reflect incursions of offshore waters into the fjord absolute abundance estimates and the preservation of lightly silicified taxa suggest excellent preservation of fossil material in the sediments of the predominantly anoxic inner basin preservation in the outer basin is reduced reflecting more frequent recharge by oxygenated waters spilling over the outer sill into the basin our findings suggest the inner basin should be an optimal site for reconstruction of diatom production with records from the outer basin providing more consistent information about offshore influence and coastal upwelling conditions over the holocene estimates of diatom abundance within the inner basin sediment may serve as a good proxy of production although proxy tracers of bottom water conditions and sedimentological analyses must be coupled to the diatom record to ensure depositional conditions were not influencing valve preservation or abundance our results suggest that fjords can serve as good environments for paleoceanographic reconstructions of both inshore and offshore conditions although careful site selection and understanding of processes affecting the microfossil record are essential

suppression of el nino during the mid holocene by changes in the earth s orbit a number of recent reports have interpreted paleoproxy data to describe the state of the tropical pacific especially changes in the behavior of the el nino southern oscillation enso over the holocene these interpretations are often contradictory especially for the eastern tropical pacific and adjacent areas of south america here we suggest a picture of the mid holocene tropical pacific region which reconciles the data enso variability was present throughout the holocene but underwent a steady increase from the mid holocene to the present in the mid holocene extreme warm el nino events were smaller in amplitude and occurred less frequently about a mean climate state with a cold eastern equatorial pacific and largely arid coastal regions as in the present climate this picture emerges from an experiment in which a simple numerical model of the coupled ocean atmosphere system in the tropical pacific was driven by orbital forcing we suggest that the observed behavior of the tropical pacific climate over the mid to late holocene is largely the response to orbitally driven changes in the seasonal cycle of solar radiation in the tropics which dominates extratropical influences

modern to late holocene deposition in an anoxic fjord on the west coast of canada implications for regional oceanography climate and paleoseismic history laminated sediments preserved in the anoxic inner basin of effingham inlet on the pacific coast of vancouver island british columbia canada yield a high resolution sediment deposition record spanning about 6000 yr the varying thickness of diatom terrigenous mud varves in sediment cores from the basin can be interpreted in terms of annual changes in surface productivity and freshwater input within the inlet similarly the occurrence of unlaminated mud units homogenites intercalated amongst the laminated sediments can be interpreted in terms of oceanic and climatic changes these units appear to be associated with coastal upwelling events that result infrequently in highly oxygenated oceanic water penetrating to the bottom of the inner and outer basins of the inlet the sedimentary record also contains massive and graded mud units considered to arise from debris flows and turbidity currents some of which were probably initiated by seismic events including a major event about 4500 14 c yr bp which may be earthquake related a total of seventeen oceanographic surveys of the inlet beginning in 1995 characterize the modern seasonal coastal upwelling regime and a unique bottom water oxygenation event which was

holocene tree line and climate change on the queen charlotte islands canada palynological study of two subalpine ponds on the queen charlotte islands reveals changes in tree line and climate during the holocene the findings agree with previous reconstructions from nearby louise pond on the queen charlotte islands that suggest a warmer than present climate and higher than present tree lines in the early holocene ca 9600 660014c yr b p basal ages at sc1 pond and shangri la bog indicate that the basins did not hold permanent water before 720014c yr b p consistent with a warmer and drier early holocene previously inferred from louise pond pollen and plant macrofossils indicate the initial establishment of subalpine conditions by 6090 9014c yr b p similar to the 5790 13014c yr b p age for cooling inferred from louise pond conditions similar to present were established at sc1 pond by 3460 10014c yr b p confirming the previous estimate of 340014c yr b p at louise pond this 340014c yr b p vegetation shift on the queen charlotte islands corresponds with the beginning of the tiedemann glacial advance in the south coastal mountains of british columbia ca 330014c yr b p the peyto and robson glacial advances between 3300 and 280014c yr b p in the rocky mountains and climatic cooling inferred from palynological studies throughout southern british columbia northern washington and southeast alaska these findings confirm that changes in regional climate influenced changes in vegetation in coastal british columbia