Fault plane solutions for northeastern United States earthquakes

1981 ◽  
Vol 71 (6) ◽  
pp. 1875-1882
Author(s):  
Jay J. Pulli ◽  
M. Nafi Toksöz
Keyword(s):  
United States ◽  
New York ◽  
New England ◽  
Fault Plane ◽  
Local Stress ◽  
P Wave ◽  
Northeastern United States ◽  
Stress Concentrations ◽  
Fault Plane Solutions ◽  
Entire Area

Abstract Fault plane solutions for eight earthquakes occurring in the northeastern United States have been determined using P-wave first motions and a computer algorithm for picking all valid solutions. The predominant mechanism in the area is thrust faulting, however the direction of the P axis is not consistent throughout the entire area. In central New England (Maine-New Hampshire), the P axis trends nearly E-W. In southeastern New England, the P axis trends N-S to NE-SW. In the Adirondacks region of New York, the P axis trends NE-SW as previously reported by Yang and Aggarwal (1981). Although the stress distribution appears to be complicated, as in the Central United States (Street et al., 1974), an underlying E-W compressive stress may exist in the New England area. These small earthquakes may represent the response to local stress concentrations.

The Age of Common Beans (Phaseolus vulgaris) in the Northeastern United States

1999 ◽  
Vol 64 (4) ◽  
pp. 653-658 ◽  
Author(s):  
John P. Hart ◽  
C. Margaret Scarry
Keyword(s):  
United States ◽  
New York ◽  
Zea Mays ◽  
Phaseolus Vulgaris ◽  
Radiocarbon Date ◽  
Common Beans ◽  
Eastern United States ◽  
Northeastern United States ◽  
Susquehanna River ◽  
Ams Dates

AbstractA radiocarbon date of A.D. 1070 ± 60 was linked to the remains of maize (Zea mays), beans (Phaseolus vulgaris), and squash (Cucñrbita pepo) at the Roundtop site in the Susquehanna River valley of New York by William Ritchie in 1969 and 1973 publications. This date established the presence of beans in the Northeast at an earlier time than in most other areas of the eastern United States, where they are generally rare before A.D. 1300. Subsequently beans have been reported in pre-A.D.1300 contexts from at least eight other sites in the Northeast. Recent calibrated AMS dates on beans from Roundtop are no earlier than A.D. 1300 (Hart 1999a). Given that the original Roundtop date was responsible for the acceptance of early beans in the Northeast, the AMS dates suggested that beans may not become archaeologically visible there until ca. A.D. 1300. AMS dates on beans from four other sites, reported here, substantiate the Roundtop results. Beans and by extension maize-beans-squash intercropping are not evident in the Northeast before ca. A.D. 1300.

Aftershocks of the February 21, 1973 Point Mugu, California earthquake

1976 ◽  
Vol 66 (6) ◽  
pp. 1931-1952
Author(s):  
Donald J. Stierman ◽  
William L. Ellsworth
Keyword(s):  
Fault Zone ◽  
Main Shock ◽  
Fault Plane ◽  
Body Wave ◽  
P Wave ◽  
Fault System ◽  
Wave Radiation ◽  
Fault Plane Solutions ◽  
Complex Deformation ◽  
Transverse Ranges

abstract The ML 6.0 Point Mugu, California earthquake of February 21, 1973 and its aftershocks occurred within the complex fault system that bounds the southern front of the Transverse Ranges province of southern California. P-wave fault plane solutions for 51 events include reverse, strike slip and normal faulting mechanisms, indicating complex deformation within the 10-km broad fault zone. Hypocenters of 141 aftershocks fail to delineate any single fault plane clearly associated with the main shock rupture. Most aftershocks cluster in a region 5 km in diameter centered 5 km from the main shock hypocenter and well beyond the extent of fault rupture estimated from analysis of body-wave radiation. Strain release within the imbricate fault zone was controlled by slip on preexisting planes of weakness under the influence of a NE-SW compressive stress.

Propagation of high-frequency (4- to 50-Hz) P waves in the northeastern United States

1995 ◽  
Vol 85 (4) ◽  
pp. 1244-1248
Author(s):  
Eric P. Chael ◽  
Patrick J. Leahy ◽  
Jerry A. Carter ◽  
Noël Barstow ◽  
Paul W. Pomeroy
Keyword(s):  
United States ◽  
Decay Rate ◽  
High Frequency ◽  
P Wave ◽  
Wave Spectra ◽  
Northeastern United States ◽  
P Waves ◽  
Geometric Spreading ◽  
Frequency Independent

Abstract We have measured the decay rate of high-frequency (4- to 50-Hz) P waves in the northeastern United States. We analyzed signals from 28 explosions of a 1988 USGS/AFGL/GSC refraction survey recorded at distances between 30 and 400 km. Over this range, the decay rate steadily increases from Δ−2 at 10 Hz to Δ−4 at 45 Hz. If one assumes geometric spreading of Δ−1.3, then the remaining decay is consistent with a nearly frequency-independent Q of about 1000. The results provide a useful parameterization for predicting P-wave spectra at near-regional ranges.

Surveillance and Monitoring of White-Tailed Deer for Chronic Wasting Disease in the Northeastern United States

2014 ◽  
Vol 5 (2) ◽  
pp. 387-393 ◽  
Author(s):  
Tyler S. Evans ◽  
Krysten L. Schuler ◽  
W. David Walter
Keyword(s):  
United States ◽  
New York ◽  
Lymph Nodes ◽  
Wildlife Management ◽  
Chronic Wasting Disease ◽  
Regional Scale ◽  
Northeastern United States ◽  
Wasting Disease ◽  
The Past ◽  
Northern Colorado

Abstract Chronic wasting disease (CWD) is a prion disease that affects both wild and captive cervid populations. In the past 45 y, CWD has spread from northern Colorado to all bordering states, as well as the midwestern United States (Midwest) and northeastern United States (Northeast), Canada, and South Korea. Because CWD is a relatively new issue for wildlife management agencies in the Northeast, we surveyed a representative (e.g., cervid biologist, wildlife veterinarian) from 14 states to gain a better understanding of state-specific surveillance measures. Between 2002 and 2012, New York (37,093) and Pennsylvania (35,324) tested the greatest number of harvested white-tailed deer Odocoileus virginianus in the Northeast. Additionally, the 14 states surveyed have tested 121,730 harvested deer, or approximately 15,216/y, since CWD was first detected in 2005. The most common tissues used by agencies in the Northeast for testing were retropharyngeal lymph nodes, which have been determined to be the most reliable in detecting CWD in cervids. Understanding CWD surveillance efforts at a regional scale can help to provide guidance for the development of new surveillance plans or the improvement of existing ones. Furthermore, collaborations among state and regional agencies in the Northeast may attempt to identify deficiencies in surveillance by state or subregion.

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