[1] High-resolution aeromagnetic surveys of the Cascade Range and Yakima fold and thrust belt (YFTB), Washington, provide insights on tectonic connections between forearc and back-arc regions of the Cascadia convergent margin. Magnetic surveys were measured at a nominal altitude of 250 m above terrain and along flight lines spaced 400 m apart. Upper crustal rocks in this region have diverse magnetic properties, ranging from highly magnetic rocks of the Miocene Columbia River Basalt Group to weakly magnetic sedimentary rocks of various ages. These distinctive magnetic properties permit mapping of important faults and folds from exposures to covered areas. Magnetic lineaments correspond with mapped Quaternary faults and with scarps identified in lidar (light detection and ranging) topographic data and aerial photography. A two-dimensional model of the northwest striking Umtanum Ridge fault zone, based on magnetic and gravity data and constrained by geologic mapping and three deep wells, suggests that thrust faults extend through the Tertiary section and into underlying pre-Tertiary basement. Excavation of two trenches across a prominent scarp at the base of Umtanum Ridge uncovered evidence for bending moment faulting possibly caused by a blind thrust. Using aeromagnetic, gravity, and paleoseismic evidence, we postulate possible tectonic connections between the YFTB in eastern Washington and active faults of the Puget Lowland. We suggest that faults and folds of Umtanum Ridge extend northwestward through the Cascade Range and merge with the Southern Whidbey Island and Seattle faults near Snoqualmie Pass 35 km east of Seattle. Recent earthquakes (M W ≤ 5.3) suggest that this confluence of faults may be seismically active today.

[1] The southern Whidbey Island fault zone (SWIF), as previously mapped using borehole data, potential field anomalies, and marine seismic reflection surveys, consists of three subparallel, northwest trending strands extending $100 km from near Vancouver Island to the northern Puget Lowland. East of Puget Sound, the SWIF makes landfall between the cities of Seattle and Everett but is concealed beneath a thick mantle of young glacial deposits and vegetation. A $20-km-wide, northwest trending swath of subparallel, low-amplitude aeromagnetic anomalies crosses this region of the Puget Lowland and is on strike with the SWIF. The most prominent aeromagnetic anomaly, the Cottage Lake lineament, extends at least 18 km and lies approximately on strike with the SWIF on Whidbey Island. Subtle scarps and topographic lineaments on Pleistocene surfaces, visible on high-resolution lidar topography at a number of locations along the SWIF, lie on or near these magnetic anomalies. In the field, scarps exhibit northeast-side-up and vertical relief of 1 to 5 m. Excavations across several lidar scarps lying on or near magnetic anomalies show evidence for multiple folding and faulting events since deglaciation, most likely above buried reverse/oblique faults. Excavations in areas away from magnetic anomalies do not show evidence of tectonic deformation. In total, paleoseismological evidence suggests that the SWIF produced at least four earthquakes since deglaciation about 16,400 years ago, the most recent less than 2700 years ago.

For over 20 years, the UK Agriculture Departments have monitored the direct effects of pesticides on beneficial insects, mainly honeybees (Apis mellifera, L.) and bumblebees (Bombus terrestris, L.), as part of the Wildlife Incident Investigation Scheme (WIIS). The Central Science Laboratory (CSL) has contributed to WIIS by providing the required laboratory skills for the determination of bee diseases and the expert analytical experience necessary to determine low-level pesticide residues and interpret these results. The results from WIIS form part of the pesticide regulatory process coordinated by the Pesticides Safety Directorate (PSD) and are published each year. This paper has reviewed the data from WIIS over the 10 year period from 1994 to 2003. The overall trend is that suspected poisoning incidents, reported by beekeepers and the general public, have declined from 56 incidents per year to 23 incidents per year. The number of these incidents that have been attributed to pesticide poisoning has also declined, from 25 incidents to five incidents per year. The possible reasons for these changes and the circumstances involved in the bee poisoning incidents are discussed. However, the source of the pesticide in bee poisoning incidents is often uncertain and the likely cause of these incidents and any trends over time are also discussed.