Report on earth tides—1939–1947

Lambert, Walter D.

doi:10.1007/bf02519087

Cited by 8 publications

(10 citation statements)

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“…Natural water-level monitoring data include the intrinsic periodicities caused by earth tides and atmospheric pressure fluctuations, which influence the water-level fluctuations in confined, unconfined, and low-porosity aquifers [28][29][30]. Because the degree of influence can differ depending on the characteristics of each aquifer, the periodic features of such signals could be used to identify the type of aquifer more specifically [31][32][33].…”

Section: Introductionmentioning

confidence: 99%

Characterising Bedrock Aquifer Systems in Korea Using Paired Water-Level Monitoring Data

Lee

Woo

Lee

et al. 2017

Water

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This study focused on characterising aquifer systems based on water-level changes observed systematically at 159 paired groundwater monitoring wells throughout Korea. Using spectral analysis, principal component analysis (PCA), and cross-correlation analysis with linear regression, aquifer conditions were identified from the comparison of water-level changes in shallow alluvial and deep bedrock monitoring wells. The spectral analysis could identify the aquifer conditions (i.e., unconfined, semi-confined and confined) of 58.5% of bedrock wells and 42.8% of alluvial wells: 93 and 68 wells out of 159 wells, respectively. Even among the bedrock wells, 50 wells (53.7%) exhibited characteristics of the unconfined condition, implying significant vulnerability of the aquifer to contaminants from the land surface and shallow depths. It appears to be better approach for deep bedrock aquifers than shallow alluvial aquifers. However, significant portions of the water-level changes remained unclear for categorising aquifer conditions due to disturbances in data continuity. For different aquifer conditions, PCA could show typical pattern and factor scores of principal components. Principal component 1 due to wet-and-dry seasonal changes and water-level response time was dominant covering about 55% of total variances of each aquifer conditions, implying the usefulness of supplementary method of aquifer characterisation. Cross-correlation and time-lag analysis in the water-level responses to precipitations clearly show how the water levels in shallow and deep wells correspond in time scale. No significant differences in time-lags was found between shallow and deep wells. However, clear time-lags were found to be increasing from unconfined to confined conditions: from 1.47 to 2.75 days and from 1.78 to 2.75 days for both shallow alluvial and deep bedrock wells, respectively. In combination of various statistical methods, three types of water-level fluctuation patterns were identified from the water-level pairs: Type I of identical aquifer systems (77.8%), Type II of the different aquifer systems with different recharge flow paths (9.5%), and Type III of unmatched aquifer system pairs and correlations (12.7%). Type I and II could be used as verification of aquifer condition in the paired monitoring system. However, Type III shows the complexity of water-level fluctuation in different aquifer conditions. This study showed that confined or not-confined conditions are not directly related to the depth of wells in the aquifer. Therefore, the utilisation of groundwater as a water-supply source should be carefully designed, tested for its hydrogeologic conditions, and managed to ensure sustainable quantity and quality.

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Section: Introductionmentioning

confidence: 99%

Characterising Bedrock Aquifer Systems in Korea Using Paired Water-Level Monitoring Data

Lee

Woo

Lee

et al. 2017

Water

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“…Earth tides are small perturbations of the shape of the earth caused by gravitational attraction from the Sun and the Moon, and are known to influence water level in wells penetrating confined aquifers or unconfined thick, low-porosity aquifers (Bredehoeft 1967;Weeks 1979). However, atmospheric pressure has greater influence, compared with earth tides, on water-level fluctuations within wells tapping unconfined aquifers (Lambert 1940;Rahi 2010). However, atmospheric pressure has greater influence, compared with earth tides, on water-level fluctuations within wells tapping unconfined aquifers (Lambert 1940;Rahi 2010).…”

Section: Introductionmentioning

confidence: 99%

“…These changes due to earth tides result in a difference in pressure between the water stored in the wellbore and the aquifer, which results in flow into or out of the well (Lambert 1940), hence waterlevel fluctuations. These changes due to earth tides result in a difference in pressure between the water stored in the wellbore and the aquifer, which results in flow into or out of the well (Lambert 1940), hence waterlevel fluctuations.…”

Section: Introductionmentioning

confidence: 99%

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Identifying Aquifer Type in Fractured Rock Aquifers using Harmonic Analysis

Rahi¹,

Halihan

2012

Groundwater

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Determining aquifer type, unconfined, semi‐confined, or confined, by drilling or performing pumping tests has inherent problems (i.e., cost and complex field issues) while sometimes yielding inconclusive results. An improved method to cost‐effectively determine aquifer type would be beneficial for hydraulic mapping of complex aquifer systems like fractured rock aquifers. Earth tides are known to influence water levels in wells penetrating confined aquifers or unconfined thick, low‐porosity aquifers. Water‐level fluctuations in wells tapping confined and unconfined aquifers are also influenced by changes in barometric pressure. Harmonic analyses of water‐level fluctuations of a thick (∼1000 m) carbonate aquifer located in south‐central Oklahoma (Arbuckle‐Simpson aquifer) were utilized in nine wells to identify aquifer type by evaluating the influence of earth tides and barometric‐pressure variations using signal identification. On the basis of the results, portions of the aquifer responded hydraulically as each type of aquifer even though there was no significant variation in lithostratigraphy. The aquifer type was depth dependent with confined conditions becoming more prevalent with depth. The results demonstrate that harmonic analysis is an accurate and low‐cost method to determine aquifer type.

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“…Sperling (1953) has shown the same effect of increased yield of oil wells at Nienhagen in Germany during low terrestrial crustal tide. The phenomenon has been further documented by Lambert (1940). According to G. L. Pekeris of the Massachusetts Institute of Technology (Lambert, 1940, p. 23), the lesser attraction of the moon during low crustal tide promotes a relaxation of fractured rock systems, resulting in a closer spacing of fractures thereby forcing fluids toward the surface.…”

Section: Introductionmentioning

confidence: 98%

Tidal and Gravity Effects Intensifying Lunar Defluidization and Volcanism

Green¹

1965

Annals of the New York Academy of Sciences

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Report on earth tides—1939–1947

Cited by 8 publications

References 0 publications

Characterising Bedrock Aquifer Systems in Korea Using Paired Water-Level Monitoring Data

Characterising Bedrock Aquifer Systems in Korea Using Paired Water-Level Monitoring Data

Identifying Aquifer Type in Fractured Rock Aquifers using Harmonic Analysis

Tidal and Gravity Effects Intensifying Lunar Defluidization and Volcanism

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