季风的发展与冰川的消失——从台湾高山末次冰期冰川发育特征说起

台湾高山有无第四纪冰川之争,经历60a后终于得到澄清．此次查明台湾雪山主峰区有3套 不同时期的冰川遗迹．如冰斗湖、冰坎、大型磨光面和擦痕以及冰碛垄等,分别命名为山庄冰阶(末 次冰期早期．44.25±3.72ka BP)、黑森林冰阶(末次冰期最盛,18.26±1.52 ka BP)、雪山冰阶(末次冰 期晚期,10.68±0.84 ka BP)尤其以早期冰川规模大为特征．澄清了地学界近65a来的怀疑,将为 全球变化研究增添新内容．     

Freshwater bryozoans of New Zealand: A preliminary survey

Five bryozoan species were encountered in a 15‐day survey of freshwater habitats in New Zealand. Listed in order of decreasing frequency these were: Fredericella sultana, Plumatella repens, P. emarginata, Paludicella articulata, and one plumatellid species not previously described. Micro‐structural features of the floatoblast annulus separate the P. repens specimens into two distinct varieties, named here P. repens typica and P. repens rugosa. Paludicella, reported almost 100 years ago from the City of Dunedin waterworks, was still found only in a single reservoir of that city. Species distribution did not correlate significantly with water temperature, current velocity, pH, or total dissolved solids. Two additional species believed to occur in New Zealand, Fredericella australiensis and Plumatella fungosa, were not seen in this brief survey. An identification key is provided for New Zealand bryozoans.     

Geoarchaeological Investigations of Midden‐Formation Processes in the Early to Late Ceramic Neolithic Levels at Çatalhöyük,Turkey ca. 8550–8370 cal BP

Anthropogenic midden deposits are remarkably well preserved at the Neolithic settlement of Çatalhöyük and provide significant archaeological information on the types and nature of activities occurring at the site. To decipher their complex stratigraphy and to investigate formation processes, a combination of geoarchaeological techniques was used. Deposits were investigated from the early ceramic to late Neolithic levels, targeting continuous sequences to examine high resolution and broader scale changes in deposition. Thin‐section micromorphology combined with targeted phytolith and geochemical analyses indicates they are composed of a diverse range of ashes and other charred and siliceous plant materials, with inputs of decayed plants and organic matter, fecal waste, and sedimentary aggregates, each with diverse depositional pathways. Activities identified include in situ burning, with a range of different fuel types that may be associated with different activities. The complexity and heterogeneity of the midden deposits, and thus the necessity of employing an integrated microstratigraphic approach is demonstrated, as a prerequisite for cultural and palaeoenvironmental reconstructions.     

Evaluation of physical, chemical and microbiological parameters of water quality in the Harris Neck estuarine marshes along the Georgia coast

Analysis of the physical, chemical and biological parameters assessing water quality in Harris Neck estuary indicated that the average dissolved oxygen level was 8.6 mg/L, it maintained moderate levels of total dissolved nitrogen (2.7-4.6 mg/L) and total dissolved phosphorous (<0.05 mg/L), chlorophyll a was above 5.0 μg/L and it is contaminated with low levels of fecal bacteria. Bifidobacterium adolescentis, a putative marker of human fecal pollution, was detected once at stations 3 and 5. Overall the Harris Neck water quality analyses indicated a relatively pristine and a healthy functioning marine environment.     

Geomagnetic field intensity: How high can it get? How fast can it change? Constraints from Iron Age copper slag

The intensity of the geomagnetic field varies over different time scales. Yet, constraints on the maximum intensity of the field as well as for its maximum rate of change are inadequate due to poor temporal resolution and large uncertainties in the geomagnetic record. The purpose of this study is to place firm limits on these fundamental properties by constructing a high-resolution archaeointensity record of the Levant from the 11th century to the early 9th century BCE, a period over which the geomagnetic field reached its maximum intensity in Eurasia over the past 50,000 years. We investigate a ¹⁴C-dated sequence of ten layers of slag material, which accumulated within an ancient industrial waste mound of an Iron Age copper-smelting site in southern Israel. Depositional stratigraphy constrains relative ages of samples analyzed for paleointensity, and ¹⁴C dates from different horizons of the mound constrain the age of the whole sequence. The analysis yielded 35 paleointenisty data points with accuracy better than 94% and precision better than 6%, covering a period of less than 350 years, most probably 200 years. We construct a new high-resolution quasi-continuous archaeointensity curve of the Levant that displays two dramatic spikes in geomagnetic intensity, each corresponding to virtual axial dipole moment (VADM) in excess of 200 ZAm². The geomagnetic spikes rise and fall over a period of less than 30 years and are associated with VADM fluctuations of at least 70 ZAm². Thus, the Levantine archaeomagnetic record places new constraints on maximum geomagnetic intensity as well as for its rate of change. Yet, it is not clear whether the geomagnetic spikes are local non-dipolar features or a geomagnetic dipolar phenomenon.     

Can ensembles of regional climate model simulations improve results from sensitivity studies?

Intrinsic variability (IV) in regional climate models (RCMs) is often assumed to be small because at climatological timescales, the model solutions tend to be dominated by the model??s lateral boundary conditions. Recent studies have indicated that this IV may actually be large in certain instances for some variables. Direct interpretation of anomalies from RCM sensitivity studies relies on the assumption that differences between model simulations are entirely due to a physical forcing. However, if IV is as large or larger than the physical signal, then this assumption is violated. Using a 20 member ensemble of RCM simulations, we verify that IV of precipitation within a RCM can be large enough to violate the sensitivity study assumption, and we show that generating ensembles of simulations can help reduce the level of IV. We also present two indicators that can rule out the influence of IV when it is ambiguous whether anomalies within a sensitivity study are due to the sensitivity perturbation or whether they are due to IV.     

Assessment of institutional capacity to adapt to climate change in transboundary river basins

Responses to climate change in transboundary river basins are believed to depend on national and sub-national capacities as well as the ability of co-riparian nations to communicate, coordinate, and cooperate across their international boundaries. We develop the first framework for assessing transboundary adaptive capacity. The framework considers six dimensions of transboundary river basins that influence planning and implementation of adaptation measures and represents those dimensions using twelve measurable indicators. These indicators are used to assess transboundary adaptive capacity of 42 basins in the Middle East, Mediterranean, and Sahel. We then conduct a cluster analysis of those basins to delineate a typology that includes six categories of basins: High Capacity, Mediated Cooperation, Good Neighbour, Dependent Instability, Self-Sufficient, and Low Capacity. We find large variation in adaptive capacity across the study area; basins in Western Europe generally have higher capacities to address the potential hazards of climate change. Our basin typology points to how climate change adaptation policy interventions would be best targeted across the different categories of basins.     

Middle to late Holocene chironomid-inferred July temperatures for the central Northwest Territories,Canada

We analyzed subfossil chironomids, sediment organic matter and sediment particle size data from a 1.11-m-long freeze core collected from Carleton Lake (unofficial name), located approximately 120 km north of the modern treeline. This well-dated core spans the last ca. 6,500 years. Two chironomid transfer functions were applied to infer mean July air temperatures. Our results indicated that the chironomid-inferred temperatures from this lake sediment record did not pass a significance test, suggesting that other factors in addition to temperature may have been important in structuring the chironomid community through time. Although not statistically significant, the chironomid-inferred temperatures from this site do follow a familiar pattern, with highest inferred temperatures occurring during the Holocene Thermal Maximum (~6–4 cal kyr BP), followed by a long-term cooling trend, which is reversed during the last 600 years. The largest change in the chironomid assemblage, which occurred between ca. 4,600 and 3,900 cal yr BP is possibly related to the well-documented northward advance and subsequent retreat of treeline in this region.     

Geological characteristics and genesis of subbottom pinnoite deposit of Da Qaidam salt lake in Qaidam Basin

正Da Qaidam salt lake is known for its both liquid and solid boron resource.Data from previous investigation of the Da Qaidam salt lake provided a comparable framework for this study that focused on investigating the section beneath the bottom of the perennial salt lake,including the timing,