Radioactive heat generation and heat flow in the Indian shield

Using a laboratory gamma-ray spectrometer, 160 rock samples from different heat flow sites in India have been analysed for their U, Th and K contents. Heat generation has been estimated for the significant rock types. Of the six regions covered by this study, correction due to heat generation contrast and geologic structure was found necessary and has been applied in two regions. Heat flow/heat generation plots for two regions in the southernmost part of the shield follow the line characteristic of a normal continental heat flow province. The plots for the other four regions indicate a heat flow province with an intercept of 0.92 HFU and a slope of 14.8 km. From data available at present, these parameters are higher compared to those from the other shields. The higher parameters imply a higher temperature and heat flow at the Moho, indicating a region of “hotter” upper mantle in the Indian shield.     

A speleothem record of Younger Dryas cooling, Klamath Mountains, Oregon, USA

A well-dated δ¹⁸O record in a stalagmite from a cave in the Klamath Mountains, Oregon, with a sampling interval of 50 yr, indicates that the climate of this region cooled essentially synchronously with Younger Dryas climate change elsewhere in the Northern Hemisphere. The δ¹⁸O record also indicates significant century-scale temperature variability during the early Holocene. The δ¹³C record suggests increasing biomass over the cave through the last deglaciation, with century-scale variability but with little detectable response of vegetation to Younger Dryas cooling.     

Giving Credit where Credit is Due. A Practical Method to Distinguish between Human and Natural Factors in Carbon Accounting

Net carbon emissions from the biosphere differ from fossil-fuel based emissions in that: (i) a large proportion of biospheric carbon exchange is not under direct human control; (ii) land-use decisions often have only a small short-term effect on net emissions, but a large long-term effect; and (iii) biospheric carbon exchange is potentially reversible. Because of these differences, carbon accounting approaches also need to be different for fossil-fuel and biosphere-based emissions. Recognising that, the international negotiators at COP 7 adopted a range of guiding principles for accounting for biospheric carbon exchange, including: that accounting excludes removals resulting from (a) elevated carbon dioxide concentrations above pre-industrial level; (b) indirect nitrogen deposition; and (c) the dynamic effects of age structure resulting from activities and practices before the reference year. In this paper, we highlight some of the challenges in biospheric carbon accounting for Canada, the U.S.A, New Zealand and Australia, four nations for which biospheric net carbon exchange is large relative to fossil-fuel based emissions. We discuss an accounting scheme that is based on assessing changes in average carbon stocks due to changes in land use. That scheme is tailored to the special needs of biospheric carbon management and is consistent with the accounting principles adopted at COP 7. The paper shows how the accounting scheme would resolve many of the biospheric carbon accounting anomalies identified for the four nations we studied.     

Palaeoenvironmental significance of trace fossils from the palaeocene sediments of the Pondicherry area,South India

Sediments of Manaveli Formation (Palaeocene) are studied from the Thondaimanattam quarry section and Manaveli section of the Pondicherry area, which comprises of bioturbated arenaceous limestone-shale and shaly-sandstone sequences respectively. These sediments consist of high density and low diversity trace fossil genera which includes Lanicodichnus, Ophiomorpha, Planolites, Palaeophycus, Skolithos, Thalassinoides, and Polychaetes tubes. The abundance of horizontal structures of the Thondaimanattam quarry section indicate low to moderate wave and current energy in fully marine subtidal environments while the presences of vertical structures of the Manaveli section indicate moderate to high wave and current energy in the marginal marine environment of deposition for the Palaeocene sediments of the Pondicherry area.     

Spawning of major carps in the lower Halda River,Bangladesh

Spawning biology and spawn fishery of three valuable species of Indian major carps,Catla catla, Labeo rohita andCirrhinus mrigala, in the lower Halda River, Bangladesh, were studied in 1978. The major carps spawned only in the Sonairchar oxbow-bend from April to June on or near the dates of the full moon and the new moon. The tide was then at its highest level, and there was heavy flood water runoff from the hill region with sharp increases in water level, turbidity and current velocity, as well as decreases in water temperature, dissolved oxygen, and hydrogen ion concentration. These three heterogeneric species, as a result of parallelism or convergence in evolution, overlap in their environmental requirements for spawning. The nursery ground of the major carp fry spawned in the Halda River was found to be in the Bay of Bengal. The brood stock origin is suspected to be at the Shankha River, 40 miles south of the Karnafuli River. The spawn fishery in the Halda River was intensive but inefficient. Engineering works and water management schemes are threatening the spawning habitat.     

Recommendation for the discrimination of human-related and natural seismicity

Various techniques are utilized by the seismological community, extractive industries, energy and geoengineering companies to identify earthquake nucleation processes in close proximity to engineering operation points. These operations may comprise fluid extraction or injections, artificial water reservoir impoundments, open pit and deep mining, deep geothermal power generations or carbon sequestration. In this letter to the editor, we outline several lines of investigation that we suggest to follow to address the discrimination problem between natural seismicity and seismic events induced or triggered by geoengineering activities. These suggestions have been developed by a group of experts during several meetings and workshops, and we feel that their publication as a summary report is helpful for the geoscientific community. Specific investigation procedures and discrimination approaches, on which our recommendations are based, are also published in this Special Issue (SI) of Journal of Seismology.     

Egg and yolk sac stages of the sand flounder (Teleostei: Pleuronectidae)

The developmental stages of the eggs and yolk‐sac larvae of the common sand flounder, Rhombosolea plebeia (Richardson), are described and illustrated.     

The directional characteristics of lunar infrared radiation

A theory of the directional characteristics of the lunar infrared radiation measured by Saari and Shorthill has been derived. This theory is in excellent agreement with experiment at all angles of observation and at all phase angles. The radiation law used to describe the angular dependence of the infrared radiation emitted by a flat element of the lunar surface is 0.85 cos + 0.22 cos², where is the angle between the surface normal and the direction of observation. This radiation law is subsequently modified by taking into account lunar surface roughness. We assume a surface covered in part with spherical craters of various depth to diameter ratios as a model for the lunar soil. Re-radiation within the craters has been accounted for. Extensive use is made of group theoretical and invariant tensor methods which enable us to show that most of the details of the radiation pattern do not depend on the detailed nature of the surface features assumed, but only on the average surface slope. A best fit to the Saari-Shorthill data has been obtained by assuming 50% of the lunar surface to be covered with craters with a depth to diameter ratio of 1:3, while the remainder of the surface is essentially flat. The mean deviation between theory and experiment is 4K.This work has been supported by the National Aeronautics and Space Administration under Contracts No. NAS8-20 385 and NAS8-25 585, Marshall Space Flight Center, Alabama.Receipt delayed due to postal strike in Great Britain.