From 1951 to 1981, the Canadian weathership program collected nearly continuous wind and wave observations at Station Papa, a common reference site in the North Pacific. The length of this time series makes it a valuable tool in determining long-term trends and statistics of North Pacific wind and waves. Due to the uncertain quality and poor documentation of the data, extensive cross-referencing and quality control of disparate data sources was performed, leading to the development of a single, high-quality dataset. To verify the accuracy and consistency of the weathership measurements, histograms of wind speed, wave height, and wave period were compared with those from modern wave buoy measurements at Station Papa, taken since 2010. While the wind measurements aligned well with the newer data, the wave observations showed notable biases. These biases are likely due to the outdated method of visually observing waves from the weatherships. A time-series model with an annual oscillation and autoregressive component was fit to the wind measurements. Such a model accurately represents both the seasonal weather cycle and short-term storm pattern at Station Papa. In addition, it was found that the wind and wave statistics were significantly correlated on interannual timescales with the El Niño Southern Oscillation (ENSO) and Pacific Decadal Oscillation (PDO). Quantifying the impacts of these trends has practical implications for predicting future changes in wind and wave climate.

The San Juan Channel links the Strait of Georgia and the Strait of Juan de Fuca, and is dominated by an estuarine flow regime. The goal of this study was to characterize the physical water properties of the San Juan Channel for autumn 2013 including the Fraser River signal in the northern channel, the oceanic signal in the south and how tides and winds affect the expression of these signals within the San Juan Channel. Finer temporal resolution data provided by the Friday Harbor Lab weather station was used to investigate how tides and winds affect the freshwater signal in the northern channel. During fall 2013, the Pelagic Ecosystem Function Research Apprenticeship sampled a 5-station transect along the San Juan Channel. A CTD was deployed and temperature, salinity, and density data were collected. From these data, channel structure could be deduced, and contour plots were created to help extrapolate the trends. Water and air temperature decreased throughout the autumn season. Short-term channel salinity and density structure was modulated by tides and winds. Density stratification was highest at South Station and North Station stratification was greatest when the freshwater signal was strongest. The depth of the pycnocline at South Station was not correlated to tidal height. However, when data points were separated by tidal cycle, there was a correlation between neap tide’s pycnocline depth and tidal height. Also, finer temporal resolution analysis of the northern channel salinity structure revealed that there is extensive within channel variation, and that salinity is regulated by tidal phase and cycle, as well as winds. The temperature, salinity and density structure patterns presented within this study, strengthen our understanding of their physical drivers within the San Juan Channel.

Low oxygen concentrations in oceans exist at mid-latitudes where water circulation occurs sluggishly, causing oxygen minimum zones (OMZ’s) to form. Recent trends suggest that OMZ’s are expanding, which could decrease biodiversity, disrupt food chains, and alter seafood industries. The low oxygen content causes OMZ’s to host denitrification, a process in which organisms use nitrate rather than oxygen in cellular respiration. Understanding these rates of denitrification will allow us to predict the consequences of climate change on nutrient cycling and ocean productivity. Autonomous floats with chemical sensors are currently being designed to quantify the rates of denitrification. To ensure that future oxygen measurements will be highly accurate, I calibrated the oxygen sensor using the Winkler method, a chemical procedure. A new amperometric titration Winkler kit was used on the R/V Oceanus to analyze saltwater and freshwater samples near the Columbia River. The data showed that as the temperature and salinity of the samples increased, oxygen content decreased. These samples had oxygen concentrations in the range of 2.4 to 6.0 mL O₂/L H₂O with approximately 1% precision. For optimization of oxygen measurements in OMZ’s, past publications suggested diluting chemicals as well as adding sodium azide. I conducted a dilution experiment involving the Winkler titrant, sodium thiosulfate. OMZ water was created in the lab by adding sucrose to seawater and measuring the oxygen content with an optode, which reported around 2% O₂ saturation. This sample was analyzed using Winkler chemicals with a tenth of the baseline concentration. However, this experiment was limited by the titration system parameters and significant data could not be collected. Revision of the system programming is necessary to finish the experiment. Additionally, further research with the sodium azide modification will increase the accuracy of oxygen measurements in OMZ's and therefore greatly advance the calibration of the oxygen sensor.

This study will characterize spatial variation within the ocean water column. Variation in ocean water characteristics is believed to occur predominantly in the upper 100m and the ocean deep is thought to be largely uniform in terms of temperature, salinity, turbidity, and fluorescence. Using remote sensing with a CTD tow-yo, surface level flow-through sensors, and acoustic backscatter profilers we will determine the spatial variation of the sampled water column. Spatial autocorrelation statistics and self-similarity of basic water properties over a spatially continuous profile will be used to characterize the spatial complexity of a sample transect between Tahiti and Western Soma. In the equatorial Pacific, we hypothesize the quantitative patchiness of fluorescence to be most closely correlated with the quantitative measure of the patchiness of light. When compared to the spatial complexity as represented by satellite observations of the ocean surface, this approach will define complexity of the vertical aspect of the ocean. Additionally, it will provide insight on how the application of satellite and ship-based technologies can be utilized for continuous, and therefore more accurate, measurements of the ocean complexity.

The Elwha is a small mountainous river that discharges into the Strait of Juan de Fuca, and is the location of largest dam removal project in U.S. history. Millions of cubic meters of fine-grained sediment that have been trapped for a century are expected to be delivered to the nearshore in the two to five years following the complete removal of the dams. Strong influxes of suspended sediment into the Strait associated with large discharge events provide a unique opportunity to gain a better understanding of the surface plume and how it transports sediment. This study used filtration, optical backscatter data, and grain size analysis to find concentration and grain size distribution of suspended sediment in the subaerial delta channels and surface plume. Since the project began, suspended sediment in the river and its surface plume has increased by two orders of magnitude. Sediment concentration increased seaward in the western distributary channel, and the highest concentrations of suspended sediment in the surface plume occurred immediately outside of the delta and decreased rapidly away from the river’s mouth. Large amounts of sand found suspended in the western channel suggest further seaward expansion of the sandy delta.

Thrust faults are a type of fault where the hanging wall is thrust on top of the foot wall. In some situations, such faults cause another thrust fault to occur in the same area, but facing the opposite direction. These are called back-thrust faults. In the Seattle Fault Zone, an area which spans from the Kitsap Peninsula through Lake Sammamish and is about 8km wide, there are three main thrust faults and five back-thrust faults. However, the expression of these faulting features on the seafloor may be masked by on-going sedimentation processes. This study focuses on an area off the East coast of Bainbridge Island in Elliot Bay near Seattle, Washington. The use of ship-based SONAR (SOund Navigation and Ranging), which produces an acoustic signal and determines depth based upon the two-way travel time of sound, was used to create bathymetric surfaces. The survey was conducted by following navigational track lines which span the survey the area in parallel lines. During the survey, acoustic signal was received by multiple beams at various angles from the center of the ship. A high-resolution multi-beam sonar survey was conducted over this area of uncertainty in fault locations. Post-processing of these data generated a three-dimensional seafloor map, or surface. The excursion was used to amplify changes in bathymetry in hopes of discovering evidence of faulting. While the locations of the back-thrust faults were not indicated on the created surface, some abnormal surface features were located along a proposed main thrust fault. These features could solidify the location of the main thrust as well as indicate recent movement along the fault.

 The population of surfers has grown rapidly over the past 50 years and the surfing industry has expanded with it. The surfing industry was calculated in 2005 to be worth $7 billion annually and has grown since then. With this increase in popularity the ‘perfect’ surf spots around the world have become overcrowed (Scarfe, 2009). Hence there is a desire for Artificial Surf reefs (ASR) that take into account coastal, ecological and surf enhancement. In order to build successful Artificial Surf Reefs (ASR) there are many parameters that need to be taken into consideration. Three important ones are breaking wave height, wave peel angle and underlying bathymetry. Combining these three parameters produces a simple ranking system for the Surfablilty of both the wave and the location. I collected data at 3 different locations in the southern hemisphere each with a different ranking to allow a good range in data (New Zealand; Te Arai & Shipwreck bay, Tahiti; Vairao). Data was collected on underlying bathymetry, wave height and wave peel angle. I hypothesized that there was a relationship between bathymetry and the surfability of waves specifically; a sharper change in bathymetry into shallower water depth regions would produce a higher ranked wave.  Wave height mesurements were collected using pressure sensors located at the seabed, for peel angle video recordings were analyzed. For bathymetry I surved each location using a depth sounder and single beam transducer.

---still working on results

One of the main areas of focus in computational geology is how to quantitatively assess the nature of geomorphic features, in particular those that cannot be directly observed, such as the seafloor. An expert may know what a feature is simply by looking at it, and will be able to expound on why the feature is what it is, but there are relatively few features for which a rigid, quantitative criteria exists, one that will define, without subjectivity, why a feature is this and not that. This project aims to develop such a criteria for the submarine features known as debris slumps, where large amounts of the seafloor along a ridge detach from the surrounding area and slowly move downwards, creating a large block of loose material. Using sonar data of a debris slump off of Samoa, several techniques are used to determine precisely where the slump begins and ends. These techniques include analysis of sediment distribution, geostatiscal models of changing depths, and analysis of slope, hill aspect, and other models of geologic change. Combining all of these results produces a distinct profile of what that debris slump quantitatively looks like. This profile can then be validated by comparing it to the profile the same suite of metrics produces for an area that is not part of a debris slump. The difference between the two profiles shows that a different set of processes are shaping each area of the seafloor, and the slump was created in a different way than the surrounding seafloor. Profiles of this nature allow marine geomorphologists, geologists, and remote sensing experts to quickly determine the identity of objects on the seafloor, and be able to assess the impact they will have on the surrounding region.