Acquisition of High Resolution Magnetometer

9617897通道这笔赠款提供161,248美元，作为购置高分辨率低温磁强计费用的一半，用于区域和全球气候变化的海洋和湖泊古地磁调查，以及研究地球地磁场相对古地磁强度的长期变化。具体地说，佛罗里达大学将获得新一代2-G企业型号755 u通道低温磁强计。该仪器能够以高分辨率和高灵敏度快速测量取自活塞或重力岩心的1.5 m段U形通道的磁特性，使用复杂的直流鱿鱼，其灵敏度比上一代配备射频(RF)鱿鱼的机器高一个数量级以上。此外，755型还配备了串联交变磁场消磁线圈和脉冲充磁器，这样可以在一次操作中测量磁芯的多个磁性，从而消除了将样品转移到不同仪器时可能出现的定位误差，并允许长时间的无人值守操作。将对在大洋钻探巡航前往北大西洋和南大西洋期间收集的沉积岩芯的长期记录进行古地磁分析，以试图通过粒度、结构和岩性变化更好地关联这些沉积物中记录的古气候信号，并更好地了解由这些岩芯中磁性矿物的相对古强度记录的地球地磁场的长期变异性。美国国家海洋和大气管理局最近决定允许对一半的活塞和重力岩心进行U形通道采样，这代表了一大批等待分析的海洋沉积物样本，肯定会在可预见的未来让古地磁界忙个不停。佛罗里达大学购买的2-G型755 u沟磁力仪将是美国境内的第二个此类磁力仪(另一个是在加州大学戴维斯分校，由Ken Verosub博士指导)，因此将代表着一个有价值的区域和国家机构，用于环境古地磁研究。***

9617897 Channell This grant provides $161,248 as one-half support of the costs of acquiring a high resolution cryogenic magnetometer for marine and lacustrine paleomagnetic investigations of regional and global climate change and studies of the secular variation of the relative paleointensity of the Earth's geomagnetic field. Specifically, the University of Florida will acquire a new generation 2-G Enterprises model 755 u-channel cryogenic magnetometer. This instrument provides the capability to rapidly measure the magnetic properties of 1.5 m sections of u-channels taken from piston or gravity cores with high-resolution and high sensitivity using sophisticated DC SQUIDS that afford over an order of magnitude greater sensitivity than the last generation of machines equipped with radio frequency (Rf) SQUIDS. In addition, the Model 755 is equipped with in-line alternating field demagnetization coils and a pulse magnetizer such that measurement of several magnetic properties of the core can be conducted in a single operation, eliminating possible positioning errors during sample transfer to different instruments and allowing long periods of unattended operation. Paleomagnetic analyses of long records of sediment cores collected during ODP cruises to the North and South Atlantic will be conducted in an attempt to better correlate the paleoclimatic signals recorded in these sediments through both grain size, textural and lithologic variations and to better understand the secular variability in the Earth's geomagnetic field as recorded by the relative paleointensity of magnetic minerals within these cores. The recent decision of ODP to allow u-channel sampling of the archive half of piston and gravity cores represents a veritable flood of marine sediment samples waiting to be analyzed and is sure to keep the paleomagnetic community busy for the foreseeable future. Acquisition of a 2-G Model 755 u-channel magnetometer by the University of Florida will be only the second of its kind within the United States (the other is at UC-Davis under the direction of Dr. Ken Verosub) and thus will represent a valuable regional and national facility for the study of environmental paleomagnetism. ***