scholarly journals Tectonic controls on nearshore sediment accumulation and submarine canyon morphology offshore La Jolla, Southern California

2010 ◽  
Vol 268 (1-4) ◽  
pp. 115-128 ◽  
Author(s):  
Nicolas Le Dantec ◽  
Leah J. Hogarth ◽  
Neal W. Driscoll ◽  
Jeffrey M. Babcock ◽  
Walter A. Barnhardt ◽  
...  
Keyword(s):  
Southern California ◽  
Sediment Accumulation ◽  
Submarine Canyon ◽  
La Jolla

Anatomy of the La Jolla Submarine Canyon system; offshore southern California

2013 ◽  
Vol 335 ◽  
pp. 16-34 ◽  
Author(s):  
C.K. Paull ◽  
D.W. Caress ◽  
E. Lundsten ◽  
R. Gwiazda ◽  
K. Anderson ◽  
...  
Keyword(s):  
Southern California ◽  
Submarine Canyon ◽  
La Jolla

scholarly journals Hidden in plain sight, Chaetopterus dewysee sp. nov. (Chaetopteridae, Annelida) – A new species from Southern California

2020 ◽  
Author(s):  
Ekin Tilic ◽  
Greg W. Rouse
Keyword(s):  
Southern California ◽  
Benthic Communities ◽  
Submarine Canyon ◽  
Micro Ct ◽  
Morphological Investigation ◽  
X Ray ◽  
Chaetopterus Variopedatus ◽  
Ct Data ◽  
La Jolla ◽  
A New Species

We describe a long-unnamed Chaetopterus Cuvier, 1830 species from southern California, using a combination of DNA barcoding and detailed morphological investigation employing high-resolution X-ray microtomography (micro-CT). Chaetopterus dewysee sp. nov. is not only one of the most dominant annelids in the benthic communities of the shallow end of the La Jolla submarine canyon, but also a well-established model for studying bioluminescence and has a published transcriptome. The description and naming of this southern Californian Chaetopterus is a step towards the much-needed revision of the group’s taxonomy and towards resolving the confusion over the ʻcosmopolitanʼ Chaetopterus variopedatus species complex. Micro-CT data showing details of both internal and external anatomy has been made freely available as the first annelid cybertype.

scholarly journals Diversity and distribution of nearshore barnacle cyprids in southern California through the 2015–16 El Niño

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7186 ◽  
Author(s):  
Malloree L. Hagerty ◽  
Nathalie Reyns ◽  
Jesús Pineda ◽  
Annette F. Govindarajan
Keyword(s):  
Species Diversity ◽  
El Niño ◽  
Thermal Stratification ◽  
Southern California ◽  
El Nino ◽  
Southern Oscillation ◽  
Balanus Glandula ◽  
Unknown Species ◽  
Before And After ◽  
La Jolla

Abundance, species diversity, and horizontal distributions of barnacle cyprids offshore of La Jolla, southern California were described from May 2014 to August 2016 to determine how the nearshore barnacle larval assemblage changed before, during, and after the 2015–16 El Niño. The entire water column was sampled at five stations located within one km of shore with water depths of 4, 6, 8, 10, and 12 m during 33 cruises that encompassed the time when El Niño conditions impacted the area. Nearshore temperature and thermal stratification was concurrently measured using a CTD. Six identified cyprid species, including Chthamalus fissus, Pollicipes polymerus, Megabalanus rosa, Tetraclita rubescens, Balanus glandula, and B. trigonus, along with four unknown species, were collected in our samples. DNA barcoding was used to confirm identifications in a subset of the larvae. C. fissus was more than eight times more abundant than any other species, and while abundance varied by species, cyprid density was highest for all species except for M. rosa before and after the El Niño event, and lower during the environmental disturbance. There were significant differences in cross-shore distributions among cyprid species, with some located farther offshore than others, along with variability in cross-shore distributions by season. C. fissus cyprids were closest to shore during spring-summer cruises when waters were the most thermally stratified, which supports previous findings that C. fissus cyprids are constrained nearshore when thermal stratification is high. Relative species proportions varied throughout the study, but there was no obvious change in species assemblage or richness associated with El Niño. We speculate that barnacle cyprid species diversity did not increase at our study site during the 2015–16 El Niño, as it has in other areas during previous El Niño Southern Oscillation events, due to the lack of anomalous northward flow throughout the 2015–16 event.

Effects of a major typhoon on sediment accumulation in Fangliao Submarine Canyon, SW Taiwan

2012 ◽  
Vol 326-328 ◽  
pp. 116-130 ◽  
Author(s):  
Richard P. Hale ◽  
Charles A. Nittrouer ◽  
James T. Liu ◽  
Richard G. Keil ◽  
Andrea S. Ogston
Keyword(s):  
Sediment Accumulation ◽  
Submarine Canyon

The Little Sycamore Site and the Early Milling Stone Cultures of Southern California

1954 ◽  
Vol 20 (2) ◽  
pp. 112-123 ◽  
Author(s):  
William James Wallace
Keyword(s):  
San Diego ◽  
Southern California ◽  
Coastal Region ◽  
San Diego County ◽  
University Of Southern California ◽  
Santa Barbara ◽  
Field Methods ◽  
Analogous Complex ◽  
La Jolla ◽  
The University

The Presence in the southern California coastal region of prehistoric cultures showing considerable use of milling stones has been recognized for some years. Attention was called to this fact by the publication in 1929 of David Banks Rogers’ Prehistoric Man of the Santa Barbara Coast. Rogers distinguished a sequence of three aboriginal cultures in the Santa Barbara area, the earliest of which (Oak Grove) was characterized by the employment of this form of grinding implement almost to the exclusion of other artifacts. In the same year Malcolm J. Rogers noted a somewhat analogous complex (now La Jolla) in western San Diego County (M. J. Rogers 1929: 456-7). Occurrences of similar assemblages have been reported upon since (Treganza and Malamud 1950; Walker 1952).An investigation conducted at the Little Sycamore site (Ven 1) in Ventura County by a class in archaeological field methods from the University of Southern California uncovered evidence of yet another milling stone complex.

Processes of sedimentation in Gollum Channel, Porcupine Seabight: submersible observations and sediment analyses

1995 ◽  
Vol 86 (1) ◽  
pp. 49-55 ◽  
Author(s):  
Alexander W. Tudhope ◽  
Terence P. Scoffin
Keyword(s):  
Water Depth ◽  
Sediment Resuspension ◽  
Sediment Accumulation ◽  
Submarine Canyon ◽  
Lophelia Pertusa ◽  
Channel System ◽  
Porcupine Seabight ◽  
Physical Measurements ◽  
Ne Atlantic Ocean ◽  
Manned Submersible

AbstractManned submersible dives were conducted in the submarine canyon channel system of Porcupine Seabight, NE Atlantic Ocean. Visual observations were made, and sediment samples collected and analysed to elucidate the nature of the sedimentary regime. In the upper part of the canyon (480-940 m water depth) sediments consisted of a mixture of terrigenous quartz rich silts and sands, skeletal carbonate of benthonic and planktonic origin and minor clay minerals and authigenic dolomite. There were localised Lophelia pertusa coral thickets on both the flanks and floor of the canyon. Sedimentary structures and physical measurements revealed there to be active transport of sediments in the canyon down to a depth of at least 940 m, effected by (?tidal) reversing currents and bioturbation. In these parts of the canyon, deposits around glacial dropstones and coral thickets indicate that there has been a maximum of 0-1 m of net sediment accumulation since the last glacial period. At 3000 m water depth, in the channel system, the sediments were fine calcareous ooze with a drape (up to 0-3 m thick) of flocculant phytoplankton detritus. At these depths, there was no evidence for present-day sediment resuspension by currents.

scholarly journals RECENT SEDIMENTARY PROCESSES IN THE WESTERN GULF OF CORINTH, GREECE: SEISMIC AND ASEISMIC TURBITIDES

2017 ◽  
Vol 50 (1) ◽  
pp. 383
Author(s):  
S. Sergiou ◽  
A. Beckers ◽  
M. Geraga ◽  
G. Papatheodorou ◽  
I. Iliopoulos ◽  
...  
Keyword(s):  
Sediment Cores ◽  
Sediment Accumulation ◽  
Submarine Canyon ◽  
Seismic Events ◽  
Mass Movements ◽  
Sedimentary Processes ◽  
Gulf Of Corinth ◽  
Active Tectonic ◽  
Geochemical Analyses ◽  
Seismic Origin

The Corinth rift is counted among the most active tectonic grabens in the world, with extension rates up to 15 mm/yr (Western part). These high extension rates are associated with very strong seismic events that are, occasionally, responsible for submarine mass movements. These movements, their consequential bottom currents, and the differential river-discharging sediment accumulation in the whole gulf, strongly affect the modern marine sedimentary processes. The definition and understanding of these processes is the main aim of this project. This is attempted through via sedimentological, mineral and geochemical analyses on sediment samples from two ~1.1 m long, sediment cores from a WE submarine canyon (10 km long, 3 km wide) that lies in the Western tip of the gulf. The general sedimentation motif reveals the presence of hemipelagic deposits which are occasionally interrupted by sandy turbidites. Occasionally, these turbidites seem to have seismic origin. The sedimentation rates range between 2.57 mm/yr in the western part and 0.67 mm/yr in the eastern part.

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