In New England, earthquakes pose a risk to the built environment. Emergency preparedness and mitigation planning are prudent in this region as older unreinforced masonry buildings and numerous critical facilities are common. New England state geological surveys cooperate with the Northeast States Emergency Consortium (NESEC) to improve risk communication with emergency managers. To that end, Connecticut, Maine, Massachusetts, and Vermont employed surficial geologic maps, deglaciation history, knowledge of the glacial stratigraphy, and professional judgment to reclassify surficial geologic material units into one of the five National Earthquake Hazards Reduction Program (NEHRP) site classifications (A, B, C, D, and E). These new classifications were used as a substitute for the HAZards U.S. Multi-Hazard (HAZUS-MH) site class value of “D,” which is used throughout New England as a default value. In addition, coding of surficial geologic materials for the five NEHRP site classifications was compared with classifications using the Wald methodology, a method that uses a slope analysis as a proxy for shear-wave velocity estimates. Comparisons show that coding to site classes using the Wald methodology underestimates categories A (high-velocity shear-wave materials, least relative hazard) and E (lowest-velocity shear-wave materials, greatest relative hazard) when evaluated side by side with coding done with the aid of surficial geologic maps. North of the glacial limit, derangement of drainage resulted in extensive ponding of meltwaters and the subsequent deposition of thick sequences of lacustrine mud. Inundation by the sea immediately following deglaciation in New England resulted in the deposition of spatially extensive and locally thick sequences of glacial marine mud. Surficial geologic maps better capture this circumstance when compared with the Wald topographic slope analysis. Without the use of surficial geologic maps, significant areas of New England will be incorrectly classified as being more stable than the site conditions that actually exist. By employing surficial geologic information, we project an improved accuracy for HAZUS-MH earthquake loss estimations, providing local and regional emergency managers with more accurate information for locating and prioritizing earthquake planning, preparedness, and mitigation projects to reduce future losses.

Abstract The Carapeba Field reservoirs, located in Campos Basin, offshore southeastern Brazil, consist of sand-rich deep-water deposits formed by amalgamated turbiditic channels, whose properties were modeled using subsurface and outcrop-analog information. Outcrop analogs have been found in the Eocene Annot Sandstone, of southern France. The main geological inputs to the reservoir modeling process include: (1) recognition of main intrareservoir stratigraphic units, (2) determination of facies continuity and connectivity, and (3) determination of shale (permeability barrier) continuity. The recognition, both in the outcrops and at the subsurface, of two hierarchical levels of intra-reservoir stratigraphic units, which are interpreted to represent the products of 4th- and 5th-order sea-level cycles, and are possible to correlate at typical offshore interwell distances, is particularly relevant to reduce flow-unit scale stratigraphic uncertainty. Facies continuity has been estimated using outcrop data calibrated to cores, well-logs, and production data. Outcrop facies continuity is used to guide facies extrapolation in the subsurface 3D model, resulting in more realistic permeability structures. Shale continuity, which is a major factor controlling fluid movement within the reservoir, is mainly resultant, in these high-energy sand-rich turbidite systems, of the frequency and intensity of erosional processes. Most shales show continuity of several hundred meters or more, with erosive “windows” appearing locally. In these areas, permeable vertical pathways connect adjacent units. Nevertheless, overlapping of semi-continuous beds causes a general tendency of lowering effective vertical permeability. The final subsurface 3D model, showing reduced effective vertical permeability and moderate horizontal anisotropy, is quite different from what is conventionally expected for sand-rich turbidite reservoirs.