A House for Athena Alea? On Two Fragments of House Models from the Sanctuary at Tegea

Papers from the third international seminar on Ancient Arcadia, held at the Norwegian Institute at Athens, 7-10 May 2002During the recent excavations below the Skopadian temple for Athena Alea at Tegea two fragments of building models were found, both in disturbed layers. It is suggested that they date to the early archaic period, presenting parallels with models from Perachora and the Argive Heraion as well as the Heraion on Samos. The models are suggested to be an expression of oikos identity of the elite families during the transition from the Late Geometric period

Distortion of Globular Clusters by Galactic Bulges

One of the external fields that influences the population of globular clusters is that due to galactic bulges. In extreme situations, perigalactic distances $r_p \le 100$ pc, globular clusters could suffer total disruption in a single passage. A more common scenario is that for cluster orbits with $r_p \ge 200$ pc. We investigate the effects of tidal forces from a bulge on the shape of globular clusters for this type of encounters. We find distortions characterized by ``twisting isophotes'' and consider the potential for observability of this effect. In the Milky Way, a typical globular cluster must pass within several hundred pc of the center to experience substantial distortion, and it is possible that this has happened recently to one or two present day clusters. We estimate that this distortion could be observed even for globulars in dense fields toward the bulge. In more extreme environments such as giant ellipticals or merger products with newly formed globulars, this effect could be more common, extending out to orbits that pass within 1 kpc of the bulge center. This would lead to a substantial shift in the eccentricity distribution of globulars in those galaxies.Comment: 12 pages, 8 figure

The Desert Hot Springs earthquakes and their tectonic environment

The Desert Hot Springs earthquake of December 4, 1948, was one of the larger recorded earthquakes of southern California, and its aftershocks have continued into 1957. The assigned epicenter is 33° 56'.4 N, 116° 23'.1 W; origin time, 15:43:16.7 P.S.T.; magnitude 6 1/2. Arrival times at local and distant stations are consistent with existing travel-time curves, except for anomalous S – P intervals at very near-by temporary stations; these unexplained anomalies cannot be attributed to varying depth of focus. Epicenters of the 72 aftershocks that have been accurately located are concentrated in a zone 18 km. long, parallel to the Mission Creek fault trace indicated by older scarps, but 5 km. north of it. Aftershock activity is markedly concentrated toward the two ends of this line. Location of the main shock suggests that fracturing started near the southeast end and progressed northwest-ward. The ground surface was not broken, except by landslides. Offset of the line of seismic activity from the trace of the Mission Creek fault suggests that the fault plane dips north. This attitude is substantiated not only by field observations, but also by first motions at stations within 6° of the epicenter, which require a combination of thrust-slip and right lateral-slip on a fault dipping north less than 66°. Inasmuch as this fault is not parallel to regional San Andreas trend, such oblique displacement is reasonable and is consistent with the tectonic pattern of other faults in this region. Five groups of earthquakes represent more than 85 per cent of the total strain release since 1933 in the 3,000 sq. km. area surrounding Desert Hot Springs. These earthquakes, in addition to the Desert Hot Springs shock, are: Morongo Valley (1947), Kitching Peak (1944), Covington Flat (1940), and San Gorgonio Mountain (1935); all are associated with known faults. The Morongo Valley earthquakes probably represent fracturing on the segment of the Mission Creek fault adjacent to that broken during the subsequent Desert Hot Springs shock

Relationship between seismicity and geologic structure in the Southern California region

Data from 10,126 earthquakes that occurred in the southern California region between 1934 and 1963 have been synthesized in the attempt to understand better their relationship to regional geologic structure, which is here dominated by a system of faults related mainly to the San Andreas system. Most of these faults have been considered “active” from physiographic evidence, but both geologic and short-term seismic criteria for “active” versus “inactive” faults are generally inadequate. Of the large historic earthquakes that have been associated with surficial fault displacements, most and perhaps all were on major throughgoing faults having a previous history of extensive Quaternary displacements. The same relationship holds for most earthquakes down to magnitude 6.0, but smaller shocks are much more randomly spread throughout the region, and most are not clearly associated with any mappable surficial faults. Virtually all areas of high seismicity in this region fall within areas having numerous Quaternary fault scarps, but not all intensely faulted areas have been active during this particular 29-year period. Strain-release maps show high activity in the Salton trough, the Agua Blanca-San Miguel fault region of Baja California, most of the Transverse Ranges, the central Mojave Desert, and the Owens Valley-southern Sierra Nevada region. Areas of low activity include the San Diego region, the western and easternmost Mojave Desert, and the southern San Joaquin Valley. Because these areas also generally lack Quaternary faults, they probably represent truly stable blocks. In contrast, regions of low seismicity during this period that show widespread Quaternary faulting include the San Andreas fault within and north of the Transverse Ranges, the Garlock fault, and several quiescent zones along major faults within otherwise very active regions. We suspect that seismic quiescence in large areas may be temporary and that they represent likely candidates for future large earthquakes. Without more adequate geodetic control, however, it is not known that strain is necessarily accumulating in all of these areas. Even in areas of demonstrated regional shearing, the relative importance of elastic strain accumulation versus fault slippage is unknown, although slippage is clearly not taking place everywhere along major “active” faults of the region. Recurrence curves of earthquake magnitude versus frequency are presented for six tectonically distinct 8500-km^2 areas within the region. They suggest either that an area of this small size or that a sample period of only 29 years is insufficient for establishing valid recurrence expectancies; on this basis the San Andreas fault would be the least hazardous zone of the region, because only a few small earthquakes have occurred here during this particular period. Although recurrence expectancies apparently break down for these smaller areas, historic records suggest that the calculated recurrence rate of 52 years for M = 8.0 earthquakes for the entire region may well be valid. Neither a fault map nor the 29-year seismic record provides sufficient information for detailed seismic zoning maps; not only are many other geologic factors important in determining seismic risk, but the strain-release or epicenter map by itself may give a partially reversed picture of future seismic expectance. Seismic and structural relationships suggest that the fault theory still provides the most satisfactory explanation of earthquakes in this region

MINNESOTA CURRENT FARM SITUATION

These papers describe the current economic conditions and outline some of the opportunities facing Minnesota farmers as they complete 1998 and develop plans for 1999. The first paper, Prospects For Farm Income in 1998, describes the variation in net farm income farmers in the Southeastern and Southwestern Farm Management Associations have experienced over the past twenty years. The possible effects of 1998's low commodity prices and government program payments on net farm income are discussed in the context of this historical variation. This paper points out that some farmers are experiencing a very good year in 1998, while others may have very low net farm income this year. Those with high incomes in 1998 may be primarily interested in opportunities to enhance their cash flow for 1999, while those experiencing financial stress during 1998 may need to consider a wider range of adjustments as they plan for the coming year. The remaining papers provide information farmers may want to consider as they plan their marketing and financial strategies for the coming year. Financial Management Alternatives outlines a wide range of financial management alternatives that can be used to deal with cash flow problems. Some of these alternatives will be of interest to farmers who have difficulty in projecting a positive net cash flow with the relatively low commodity prices being projected for 1999. Others are of primary interest to farmers who have relatively high debt levels and must find ways to improve both their net cash flow and their debt/asset position. Some observers have suggested that the low commodity prices projected for 1999 may lead to reductions in cash rental rates. The paper, Cropland Rental Market Impacts of Low Crop Prices, discusses a procedure to estimate "fair rental rates", and provides an historical perspective of the impact low commodity prices have had on land rental rates. The remaining two papers, Situation and Outlook For the Livestock Sector, and Considerations in Developing a Corn/Soybean Marketing Plan for 1998/1999, discuss the major factors to evaluate and options to consider in developing a marketing plan for corn, soybeans, hogs and cattle for the coming year.Farm Management,

Minimal recorded earthquakes

The magnitude of an earthquake was originally defined (Richter, 1935) as the common logarithm of the maximum displacement, expressed in microns, of the trace written by a standard torsion seismometer at an epicentral distance of 100 kilometers. When this trace amplitude is one micron the magnitude is accordingly zero