Locating a strand of the Seattle Fault Zone in southeast Seattle, Washington through topographic analysis, borehole analysis and ground penetrating radar

Contributing to the evaluation of seismic hazards, a previously unmapped strand of the Seattle Fault Zone (SFZ), cutting across the southwest side of Lake Washington and southeast Seattle, is located and characterized on the basis of bathymetry, borehole logs, and ground penetrating radar (GPR). Previous geologic mapping and geophysical analysis of the Seattle area have generally mapped the locations of some strands of the SFZ, though a complete and accurate understanding of locations of all individual strands of the fault system is still incomplete. A bathymetric scarp-like feature and co-linear aeromagnetic anomaly lineament defined the extent of the study area. A 2-dimensional lithology cross-section was constructed using six boreholes, chosen from suitable boreholes in the study area. In addition, two GPR transects, oblique to the proposed fault trend, served to identify physical differences in subsurface materials. The proposed fault trace follows the previously mapped contact between the Oligocene Blakeley Formation and Quaternary deposits, and topographic changes in slope. GPR profiles in Seward Park and across the proposed fault location show the contact between the Blakeley Formation and unconsolidated glacial deposits, but it does not constrain an offset. However, north-dipping beds in the Blakely Formation are consistent with previous interpretations of P-wave seismic profiles on Mercer Island and Bellevue, Washington. The profiles show the mapped location of the aeromagnetic lineament in Lake Washington and the inferred location of the steeply-dipping, high-amplitude bedrock reflector, representing a fault strand. This north-dipping reflector is likely the same feature identified in my analysis. I characterize the strand as a splay fault, antithetic to the frontal fault of the SFZ. This new fault may pose a geologic hazard to the region.

Recreation and trauma: An exploratory study of how specialized recreation organizations address the needs of their unique clientele

Thesis (Master's)--University of Washington, 2016-06

Clinical and functional outcomes of acute lower extremity compartment syndrome at a Major Trauma Hospital

Background: Acute lower extremity compartment syndrome (CS) is a condition that untreated causes irreversible nerve and muscle ischemia. Treatment by decompression fasciotomy without delay prevents permanent disability. The use of intracompartmental pressure (iCP) measurement in uncertain situations aids in diagnosis of severe leg pain. As an infrequent complication of lower extremity trauma, consequences of CS include chronic pain, nerve injury, and contractures. The purpose of this study was to observe the clinical and functional outcomes for patients with lower extremity CS after fasciotomy. Methods: Retrospective chart analysis for patients with a discharge diagnosis of CS was performed. Physical demographics, employment status, activity at time of injury, injury severity score, fracture types, pain scores, hours to fasciotomy, iCP, serum creatine kinase levels, wound treatment regimen, length of hospital stay, and discharge facility were collected. Lower extremity neurologic examination, pain scores, orthopedic complications, and employment status at 30 days and 12 months after discharge were noted. Results: One hundred twenty‑four patients were enrolled in this study. One hundred and eight patients were assessed at 12 months. Eighty‑one percent were male. Motorized vehicles caused 51% of injuries in males. Forty‑one percent of injuries were tibia fractures. Acute kidney injury occurred in 2.4%. Mean peak serum creatine kinase levels were 58,600 units/ml. Gauze dressing was used in 78.9% of nonfracture patients and negative pressure wound vacuum therapy in 78.2% of fracture patients. About 21.6% of patients with CS had prior surgery. Nearly 12.9% of patients required leg amputation. Around 81.8% of amputees were male. Sixty‑seven percent of amputees had associated vascular injuries. Foot numbness occurred in 20.5% of patients and drop foot palsy in 18.2%. Osteomyelitis developed in 10.2% of patients and fracture nonunion in 6.8%. About 14.7% of patients underwent further orthopedic surgery. At long‑term follow‑up, 10.2% of patients reported moderate lower extremity pain and 69.2% had returned to work. Conclusion: Escalation in leg pain and changes in sensation are the cardinal signs for CS rather than reliance on assessing for firm compartments and pressures. The severity of nerve injury worsens with the delay in performing fasciotomy. Standardized diagnostic protocols and wound treatment strategies will result in improved outcomes from this complication.

Restoring function after neuromuscular trauma: novel paradigms for enhancing volitional control of neural activity in untethered environments and vHAB, a gamified therapy platform

Thesis (Ph.D.)--University of Washington, 2016-08