The Impact of Hydrodynamics, Authigenesis, and Basin Morphology On Sediment Accumulation In An Upwelling Environment: The Miocene Monterey Formation At Shell Beach and Mussel Rock (Pismo and Santa Maria Basins, Central California, U.S.A.)

2017 ◽  
Vol 87 (9) ◽  
pp. 986-1018 ◽  
Author(s):  
Karl B. Föllmi ◽  
Patrick Thomet ◽  
Samuel Lévy ◽  
Eric De Kaenel ◽  
Jorge E. Spangenberg ◽  
...  
2013 ◽  
Vol 1 (1) ◽  
pp. 13-27 ◽  
Author(s):  
T. J. Coulthard ◽  
M. J. Van de Wiel

Abstract. Sediment yields from river basins are typically considered to be controlled by tectonic and climatic drivers. However, climate and tectonics can operate simultaneously and the impact of autogenic processes scrambling or shredding these inputs can make it hard to unpick the role of these drivers from the sedimentary record. Thus an understanding of the relative dominance of climate, tectonics or other processes in the output of sediment from a basin is vital. Here, we use a numerical landscape evolution model (CAESAR) to specifically examine the relative impact of climate change, tectonic uplift (instantaneous and gradual) and basin morphology on sediment yield. Unexpectedly, this shows how the sediment signal from significant rates of uplift (10 m instant or 25 mm a−1) may be lost due to internal storage effects within even a small basin. However, the signal from modest increases in rainfall magnitude (10–20%) can be seen in increases in sediment yield. In addition, in larger basins, tectonic inputs can be significantly diluted by regular delivery from non-uplifted parts of the basin.


2021 ◽  
Vol 9 (07) ◽  
pp. 112-118
Author(s):  
Dra. Flor Calvanapon Alva ◽  
◽  
Mg. Karina Cardenas Rodriguez ◽  
Silvia Cespedes Esquivel ◽  
Roxana Lujan Rodriguez ◽  
...  

In order to determine the impact of the construction budget on the construction costs of the Santa Maria Corporation SAC-2020, an applied research was carried out, qualitative approach, non-experimental design and correlational scope, the sample are works executed in times of health crisis the school buildings No. 81540 San Francisco de Asis and No. 80638 Americo Aguilar Celis, in the province of Viru. Thestudytechniqueused was documentary analysis and the instrument was a record card. The data obtained were processed to evaluate the incidence of the variables by means of statistical tables where it was found that 4.29% additional materials were used for the first work and 4.33% additional for the second, with respect to the budget in the case of direct general expenses, 18.75% and 23.33% respectively, additional to the estimate. It is concluded that the construction budget has a negative impact on the construction costs of Corporacion Santa Maria SAC-2020 in times of sanitary crisis, observing relevant variations between the estimated and executed costs, not obtaining the expected profit margin noting that in the case of the first project the profit margin is only 10% of the estimate and in the second projectitis 0%.


2020 ◽  
Vol 11 (1) ◽  
Author(s):  
David B. Kemp ◽  
Peter M. Sadler ◽  
Veerle Vanacker

AbstractHumans are primary agents of geomorphic change, and rates of anthropogenic landscape change likely far exceed the pace of change expected from natural geologic processes. Nevertheless, our understanding of the impact of humans on the natural landscape is limited by difficulties in accurately comparing past and present rates of change across wide spatial and temporal scales. Here, we present a compilation of  >4000 rates of alluvial sediment accumulation that provide an indirect record of North American erosion, mass transfer and sediment storage from the late Pleistocene to the present day. Continent-wide rates of alluvium accumulation were broadly stable for ~40,000 years, but increased 10-fold during the rapid expansion of agriculture and river system modification associated with European colonization. Interpreted in terms of mass transfer, humans have moved as much sediment in North America in the past century as natural processes can transfer in 700–3000 years.


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