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Islam, R.
- Comparative Study of Soil Profiles Developed on Metavolcanic (Basaltic) Rocks in Two Different Watersheds of Garhwal Himalaya
Abstract Views :219 |
PDF Views:96
Authors
Affiliations
1 Wadia Institute of Himalayan Geology, Dehradun 248 001, IN
2 H.N.B. Garhwal University (Srinagar), Srinagar 246 174, IN
1 Wadia Institute of Himalayan Geology, Dehradun 248 001, IN
2 H.N.B. Garhwal University (Srinagar), Srinagar 246 174, IN
Source
Current Science, Vol 108, No 4 (2015), Pagination: 699-707Abstract
Soil profiles are rarely preserved in the Himalaya due to active tectonics and erosion. We have studied two rarely well-preserved soil profiles developed on metavolcanic rocks namely Alaknanda soil profile (ASP) and Bhilangna soil profile (BSP) in Alaknanda and Bhilangna watersheds of the Garhwal Himalaya. Geochemical studies were carried out to understand the elemental mobility with reference to the least altered rock (LAR) in both the profiles and are compared. Differences in major element behaviour noticed are depletion of Ca and K in ASP, and depletion of Ca and Na in BSP. Trace elements also show variable mobility such as leaching of Rb, U and enrichment of Sr, Ni in ASP. In BSP, behaviour of these elements is just the opposite. Accumulation of ΣREEs in saprolitic layer and depletion in regolith of ASP suggest that rare earth element (REE) mobility took place during advanced stages of weathering. In BSP, increase in REE content from LAR to regolith suggests dominance of chemical weathering over physical weathering. This is also reflected in chemical index of alteration values which suggest variation of climatic parameters such as rainfall in the region.Keywords
Climate–Tectonic Interaction, Geochemical Behaviour, Lesser Himalaya, Physical and Chemical Alterations, Weathering.Full Text
- Instrument for Lunar Seismic Activity Studies on Chandrayaan-2 Lander
Abstract Views :1930 |
PDF Views:105
Authors
J. John
1,
V. Thamarai
1,
M. M. Mehra
1,
Teena Choudhary
1,
M. S. Giridhar
1,
Ashwini Jambhalikar
1,
Gogulapati Supriya
1,
Gaurav Saxena
1,
K. V. Shila
1,
B. Ramesh
1,
T. K. Pratheek
1,
Deepak Kumar Sharma
1,
R. Islam
1,
P. Selvaraj
1,
A. Kalpana
1,
S. Ajith Kumar
1,
K. V. Sriram
1,
A. S. Laxmiprasad
1
Affiliations
1 Laboratory for Electro-Optics Systems, Indian Space Research Organisation, Peenya 1st Stage, 1st Cross, Bengaluru 560 058, IN
1 Laboratory for Electro-Optics Systems, Indian Space Research Organisation, Peenya 1st Stage, 1st Cross, Bengaluru 560 058, IN
Source
Current Science, Vol 118, No 3 (2020), Pagination: 376-382Abstract
Instrument for Lunar Seismic Activity Studies (ILSA) is a science payload with the objective of studying seismic activities at the landing site of Vikram, the Lander of Chandrayaan-2. ILSA will be deployed to the lunar surface by a specially built mechanism. It is an indigenously developed instrument based on microelectro mechanical systems technology. High sensitivity silicon micro-machined accelerometer is the heart of the instrument that measures ground acceleration due to lunar quakes. The instrument has the capability of resolving acceleration better than 100 nano-g Hz–1/2 up to a range of 0.5 g over bandwidth of 40 Hz. This paper presents the basic concepts in the design, realization, characterization and the performance test results of the space qualified strong motion seismic sensors.Keywords
Lunar Quakes, MEMS, Seismometer, Strong Motion Sensors.Full Text
References
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- John, J. et al., Design and fabrication of silicon micro structure for seismometer, ISSS International Conference on Smart Materials, Structures and Systems, Bengaluru, 2014.
- IEEE standard specification format guide and test procedure for linear single axis nongyroscopic accelerometers IEEE Std 1293, 1998 (R2008).