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Magnetic Survey (magnetic + survey)

Distribution by Scientific Domains

Earth and Environmental Science	80%
Physics and Astronomy	20%

Selected Abstracts

Magnetic survey in the investigation of sociopolitical change at a Late Bronze age fortress settlement in northwestern Armenia

ARCHAEOLOGICAL PROSPECTION, Issue 1 2010
Ian Lindsay
Abstract The construction of large stone fortresses across much of northern Armenia during the Late Bronze Age (ca. 1500,1150 BC) represented a shift away from centuries of nomadic pastoralism, and also marked a profound transformation in the constitution of political authority and how social orders were mediated through the built environment. To date, however, little archaeological attention has been given to Late Bronze Age (LBA) settlements located outside the fortress citadels, partly due to the difficulty in detecting them from the surface. In this report we highlight results and observations from a magnetic gradiometry survey in northwestern Armenia where we test the hypothesis that an extensive LBA domestic complex existed at the base of the fortified hill at the site of Tsaghkahovit. The study surveyed four grids in the settlement area at the base of fortress. Three test units were excavated in three of the four survey areas to test selected anomalies. Two of the test units confirmed the presence of subsurface LBA deposits, including basalt stone walls, burned features, and a storage pit, appearing in the data as large dipoles. The spatial configurations of buildings revealed by the gradiometry surveys elucidate the extent of the Tsaghkahovit settlement and the formal differentiation of domestic and institutional spaces as new architectural traditions emerge during the Middle to Late Bronze Age transition. However, targeted subsurface tests also hint at the ephemeral nature of the domestic constructions suggesting the retention of mobility among subject populations under the authority of settled fortress elites. Copyright © 2009 John Wiley & Sons, Ltd. [source]

Magnetic survey at Venta Icenorum, Caistor St Edmund: Survey strategies and initial results

ARCHAEOLOGICAL PROSPECTION, Issue 4 2009
D. Bescoby
Abstract This short report summarizes two seasons of magnetic surveying at the Roman town of Venta Icenorum at Caistor St Edmund, Norfolk. Survey strategies have been developed utilizing caesium vapour magnetometers mounted on a wheeled platform with a global positioning system to map former areas of settlement and their immediate hinterlands. The resulting survey system has enabled the rapid collection of high-resolution magnetic data over an area of 30,ha, providing a detailed magnetic map of the former town. Details of the system configuration and survey strategy are described and data from the survey presented. Copyright © 2009 John Wiley & Sons, Ltd. [source]

Magnetic survey of emission line B-type stars with FORS 1 at the VLT,

ASTRONOMISCHE NACHRICHTEN, Issue 7 2009
S. Hubrig
Abstract We report the results of our search for magnetic fields in a sample of 16 field Be stars, the binary emission-line B-type star , Sgr, and in a sample of fourteen members of the open young cluster NGC3766 in the Carina spiral arm. The sample of cluster members includes Be stars, normal B-type stars and He-strong/He-weak stars. Nine Be stars have been studied with magnetic field time series obtained over ,1 hour to get an insight into the temporal behaviour and the correlation of magnetic field properties with dynamical phenomena taking place in Be star atmospheres. The spectropolarimetric data were obtained at the European Southern Observatory with the multi-mode instrument FORS1 installed at the 8m Kueyen telescope. We detect weak photospheric magnetic fields in four field Be stars, HD 62367, , Cen, o Aqr, and , Tuc. The strongest longitudinal magnetic field, ,Bz, = 117 ± 38 G, was detected in the Be star HD 62367. Among the Be stars studied with time series, one Be star, , Eri, displays cyclic variability of the magnetic field with a period of 21.12 min. The binary star , Sgr, in the initial rapid phase of mass exchange between the two components with strong emission lines in the visible spectrum, is a magnetic variable star, probably on a timescale of a few months. The maximum longitudinal magnetic field ,Bz, = ,102 ± 10 G at MJD 54333.018 was measured using hydrogen lines. The cluster NGC3766 seems to be extremely interesting, where we find evidence for the presence of a magnetic field in seven early B-type stars out of the observed fourteen cluster members (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Geophysical exploration of Guajará, a prehistoric earth mound in Brazil

GEOARCHAEOLOGY: AN INTERNATIONAL JOURNAL, Issue 3 2003
Bruce W. Bevan
An interdisciplinary team studied Guajará, a prehistoric artificial mound in the Brazilian Amazon. The geophysical surveys and excavations were interactive;this interaction furnished more information than either geophysics or excavation alone could have provided. While seven different geophysical methods were applied, the magnetic survey reported here was particularly valuable. A detailed interpretation of this survey quantified the magnetic material in the mound, and this furnished an initial estimate of the number of cooking hearths in the mound. Ten test excavations were concentrated at magnetic anomalies. These excavations located cooking hearths and burial urns. A reevaluation of the magnetic survey was then done in order to refine the estimate of the number of hearths in the mound; this yielded an estimate of 2200 hearths. This allowed the population of the site to be approximated at 78,156 people. The geophysical survey and excavations also identified possible locations for subsequent broad-area excavations. © 2003 Wiley Periodicals, Inc. [source]

Discovery of magnetic fields in the , Cephei star ,1 CMa and in several slowly pulsating B stars,

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY: LETTERS (ELECTRONIC), Issue 1 2006
S. Hubrig
ABSTRACT We present the results of a magnetic survey of a sample of eight , Cephei stars and 26 slowly pulsating B (SPBs) stars with the FOcal Reducer low dispersion Spectrograph at the Very Large Telescope. A weak mean longitudinal magnetic field of the order of a few hundred Gauss is detected in the , Cephei star ,1 CMa and in 13 SPB stars. The star ,1 CMa becomes the third magnetic star among the , Cephei stars. Before our study, the star , Cas was the only known magnetic SPB star. All magnetic SPB stars for which we gathered several magnetic field measurements show a field that varies in time. We do not find a relation between the evolution of the magnetic field with stellar age in our small sample. Our observations imply that , Cephei and SPB stars can no longer be considered as classes of non-magnetic pulsators, but the effect of the fields on the oscillation properties remains to be studied. [source]

A multiscale approach for reconstructing archaeological landscapes: Applications in Northern Apulia (Italy)

ARCHAEOLOGICAL PROSPECTION, Issue 3 2009
Marcello Ciminale
Abstract This paper is focused on the joint use of multiscale remote sensing technologies for supporting archaeological prospection. Satellite imagery, aerial photographs and high-resolution magnetic surveys were adopted for studying the Tavoliere, an extended agricultural region located in Northern Apulia (Italy) that is characterized by an abundant presence of archaeological sites. A first recognition of the archaeological features was performed by historical aerial photographs and satellite QuickBird images were used to obtain an up-to-date synoptic view of the study area. Archaeological features extracted from both aerial and satellite images, were further investigated by high-resolution magnetic survey, which provided detailed identification of buried remains. All data were stored in a GIS in order to integrate them properly. This database was used to cross-check information of different types and determine significant correlations. The multilayer analysis in the GIS environment allowed for a comprehensive reconstruction of ancient landscapes and their palaeoenvironmental context, as well as the present geomorphological and territorial setting. Moreover it represents an open information system that could always be upgraded by inputting new data from future studies. Results from our analyses suggest that this multidisciplinary and multiscale approach, in addition to its important scientific implications, could yield meaningful information for the preservation, monitoring and management of the cultural resource, from a single site to a landscape perspective; thus this integrated tool could play a strategic role in defining proper policies of sustainable development in this region. Copyright © 2009 John Wiley & Sons, Ltd. [source]

Determination of grave locations in Dedemezari Necropolis (Western Turkey) using magnetic field derivatives

ARCHAEOLOGICAL PROSPECTION, Issue 4 2008
A. Büyüksaraç
Abstract The location of the study area for this research of a Middle Bronze Age Necropolis is situated in the west of Turkey near Afyonkarahisar. Magnetic surveying was carried out in two adjacent areas (Areas 4 and 5). Four trenches have been excavated so far and graves were located in positions interpreted from a magnetic survey carried out in 2005. Initial excavations have shown that cist, pithos and simple graves were placed randomly and it is suggested that Dedemezari Necropolis is similar to the well known necropoleis of Gordion and Sariket. This paper compares the results of some phase-based filters which show improved performance as edge detectors in different ways. The filters are demonstrated on synthetic magnetic data and magnetic field data from Dedemezari Necropolis. Magnetic field derivatives, both vertical and horizontal, are common and useful tools for interpretation of the magnetic anomalies. Interpretation of magnetic field derivatives, separately or together, provide images of shallow bodies from magnetic data. The horizontal derivatives of the total magnetic field were computed in the space domain by means of finite-difference relationships, and the vertical derivative was computed in the frequency domain by using fast Fourier transform filtering. Derivatives of the magnetic anomalies have been used for detection of causative bodies. The analytic signal (AS), the enhanced horizontal derivative (EHD), tilt derivative (TD), theta map, hyperbolic tilt angle (HTA) and total horizontal derivative (THDR) methods were applied not only to synthetic anomalies but also to the measured magnetic anomalies of Areas 4 and 5. However, AS and EHD produced the best results as the other methods created edge effects. Copyright © 2008 John Wiley & Sons, Ltd. [source]

New approach to the study of city planning and domestic dwellings in the ancient Near East

ARCHAEOLOGICAL PROSPECTION, Issue 2 2007
Christophe BenechArticle first published online: 8 MAY 200
Abstract This paper presents the results of a magnetic survey on the Hellenistic and Roman site of Doura- Europos in Syria. The interpretation of the magnetic data is based on an original approach by considering the use of space in a domestic unit. This type of study has been developed for sociological research but is adapted to the information carried within geophysical data. After a brief presentation of the role of geophysical methods for the study of city planning, the most important components of the ,space syntax' will be presented and applied to two blocks of Doura-Europos, one that has been excavated in the twentieth century by the Yale University and another surveyed using the magnetic method. Copyright © 2007 John Wiley & Sons, Ltd. [source]

Complementary integrated geophysical investigation around Al-Zayyan temple, Kharga oasis, Al-Wadi Al-Jadeed (New Valley), Egypt

ARCHAEOLOGICAL PROSPECTION, Issue 3 2005
M. A. Atya
Abstract Qasr Al-Zayyan or Al-Zayyan temple in Al-Kharga oasis is documented as a node in the fortress chain that was built by the Romans to secure Darb Al-Arbain; the slaver's trade caravan route between Asyuit and Sudan. The historical and archaeological background of the temple is very scarce; it has been ascribed to Amenebis and was restored during the reign of Emperor Antoninus AD 138,161. In March 2001, an integrated ground-penetrating radar (GPR) and magnetic survey to the west of the temple showed the possibility of an existing structural complex intersecting the present temple at about 45°. It was interpreted as a multigate structure or a tomb complex. In March 2002, the relative topographic elevations were measured and the surface archaeological features were marked on a map. Also a complementary integrated geophysical survey including electromagnetic, geomagnetic and GPR was conducted along northern and western extensions of, and partially covering, the formerly prospected structure in the survey of 2001. It was designed to verify the structure, to define its extent on both the northern and western sides, and to decide about a possible excavation. The results verified the formerly prospected structure of 2001; some of its particular features have been detected. The structure therefore has been mapped over the surveyed area at the northern and western parts of the 2001 structure and it might extend wider than the surveyed area. The former proposition of a multigate structure becomes stronger because of its general appearance, and the idea of a tomb complex still exists owing to the presence of some depressions thought to be graves. Copyright © 2005 John Wiley & Sons, Ltd. [source]

Geophysical surveys at King Lobengula's Palace KoBulawayo, Zimbabwe

ARCHAEOLOGICAL PROSPECTION, Issue 1 2005
C. Gaffney
Abstract This report covers the application of magnetic survey, primarily using a magnetic susceptibility field instrument, at the historically attested site of KoBulawayo, Zimbabwe. The approximate position of the site was known before the geophysical survey took place; it was believed to comprise a Royal Enclosure, a surrounding open space possibly used as a military parade ground and the Commoner/Peripheral Settlement of Lobengula, King of the Ndebele. Occupation at the site was short lived and after only 11 years the capital of the Ndebele state was destroyed by fire in 1881. A pilot survey was undertaken in 1994 to assess the suitability of survey techniques. Consequently, a second, more extensive survey was carried out in late 1996 and early 1997 with the intention of delimiting the Royal Enclosure. Further periods of data collection took place later in 1997 and in 1998. This report describes the methods used and the interpretation of the geophysical results in the context of the understanding and management of this important historical site. Additionally, some of the results of the geophysical work have been tested by excavation and a discussion of the correlation between these data sets is also reported in this article. Copyright © 2004 John Wiley & Sons, Ltd. [source]

Ground-penetrating radar and magnetic survey to the west of Al-Zayyan Temple, Kharga Oasis, Al-Wadi Al-Jadeed (New Valley), Egypt

ARCHAEOLOGICAL PROSPECTION, Issue 2 2002
Dr. Hiroyuki Kamei
Abstract Al-Zayyan Temple or Qasr Al-Zayyan might be regarded as one in a chain of several fortresses that the Romans built to secure the salver's trade caravan route between Asyut and Sudan, known as Darb Al-Arbain. Al-Zayyan temple lies about 25 km south of Al-Kharga city, the capital of the New Valley, and deviates to the east of Al-Kharga-Paris main road some 2 km along the Al-Zayyan-Aarif minor road. The background information about the temple is very scarce, and even what is known is neither clear nor accurate. Some indications have ascribed it to Amenebis and that it was restored during the reign of Emperor Antoninus (AD 138,161). An integrated ground-penetrating radar (GPR)survey using the SIR 2000 Geophysical Survey Systems, Inc. (GSSI) together with magnetic survey using FM36 (GeoScan) and the three component fluxgate gradiometer TRM-70D (Tokin) have been applied to the western side of the temple. The results show relatively large-scale buried structures in a direction intersecting that of the present temple at about 45°. Some particular features within the structure have been speculatively ascribed on the basis of comprehending their signatures in the GPR sections. The magnetic results have improved the identification of some objects revealed by the GPR and provided ideas about some of the other features. Copyright © 2002 John Wiley & Sons, Ltd. [source]

New magnetic field measurements of , Cephei stars and slowly pulsating B stars,

ASTRONOMISCHE NACHRICHTEN, Issue 4 2009
S. Hubrig
Abstract We present the results of the continuation of our magnetic survey with FORS 1 at the VLT of a sample of B-type stars consisting of confirmed or candidate , Cephei stars and Slowly Pulsating B (hereafter SPB) stars, along with a small number of normal B-type stars. A weak mean longitudinal magnetic field of the order of a few hundred Gauss was detected in three , Cephei stars and two stars suspected to be , Cephei stars, in five SPB stars and eight stars suspected to be SPB stars. Additionally, a longitudinal magnetic field at a level larger than 3, has been diagnosed in two normal B-type stars, the nitrogen-rich early B-type star HD 52089 and in the B5 IV star HD 153716. Roughly one third of , Cephei stars have detected magnetic fields: Out of 13 , Cephei stars studied to date with FORS 1, four stars possess weak magnetic fields, and out of the sample of six suspected , Cephei stars two show a weak magnetic field. The fraction of magnetic SPBs and candidate SPBs is found to be higher: Roughly half of the 34 SPB stars have been found to be magnetic and among the 16 candidate SPBs eight stars possess magnetic fields. In an attempt to understand why only a fraction of pulsating stars exhibit magnetic fields, we studied the position of magnetic and non-magnetic pulsating stars in the H-R diagram. We find that their domains in the H-R diagram largely overlap, and no clear picture emerges as to the possible evolution of the magnetic field across the main sequence. It is possible that stronger fields tend to be found in stars with lower pulsating frequencies and smaller pulsating amplitudes. A somewhat similar trend is found if we consider a correlation between the field strength and the v sin i -values, i.e. stronger magnetic fields tend to be found in more slowly rotating stars (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

A multiscale approach for reconstructing archaeological landscapes: Applications in Northern Apulia (Italy)

Ground penetrating radar survey over a Roman building at Groundwell Ridge, Blunsdon St Andrew, Swindon, UK

ARCHAEOLOGICAL PROSPECTION, Issue 1 2004
N. T. Linford
Abstract A ground penetrating Radar (GPR) survey was conducted over well-preserved building remains revealed during a previous geophysical survey (1996) covering an apparent complex of Roman activity discovered at Groundwell Ridge to the north of Swindon, UK. Despite unfavourable, clay-rich soil conditions, the GPR survey provided a detailed plan of the Roman remains to a depth of approximately 1,m, confirming their survival in the very near surface. The GPR results complement the previous earth resistance and magnetic surveys and, together, the data suggest the presence of a high status Roman building, possibly incorporating thermoremanent features, for instance associated with a hypocaust system. Copyright © 2004 John Wiley & Sons, Ltd. [source]