The paradox of island evolution

2022 ◽  
Author(s):  
K. C. Burns
Keyword(s):  
Island Evolution

DEVELOPING A MULTIDISCIPLINARY UNDERSTANDING OF BARRIER ISLAND EVOLUTION

2017 ◽  
Author(s):  
Phillipe A. Wernette ◽  
◽  
Chris Houser ◽  
Bradley Allen Weymer ◽  
Mark E. Everett ◽  
...  
Keyword(s):  
Barrier Island ◽  
Island Evolution

INVESTIGATING BARRIER ISLAND EVOLUTION THROUGH SEDIMENT CORE ANALYSIS AND GEOPHYSICAL SURVEYS

2017 ◽  
Author(s):  
Larry Tuttle ◽  
◽  
Cassie Mohkami ◽  
Phillipe A. Wernette ◽  
Chris Houser
Keyword(s):  
Sediment Core ◽  
Barrier Island ◽  
Core Analysis ◽  
Island Evolution ◽  
Geophysical Surveys

scholarly journals The Spatio-Temporal Evolution of River Island Based on Landsat Satellite Imagery, Hydrodynamic Numerical Simulation and Observed Data

2018 ◽  
Vol 10 (12) ◽  
pp. 2046 ◽  
Author(s):  
Haiyun Shi ◽  
Yuhan Cao ◽  
Changming Dong ◽  
Changshui Xia ◽  
Chunhui Li
Keyword(s):  
Numerical Simulation ◽  
Temporal Evolution ◽  
Thematic Mapper ◽  
Sediment Discharge ◽  
Natural Factor ◽  
River Islands ◽  
Island Evolution ◽  
Spatio Temporal ◽  
Landsat Satellite ◽  
Changing Rate

A river island is a shaped sediment accumulation body with its top above the water’s surface in crooked or branching streams. In this paper, four river islands in Yangzhong City in the lower reaches of the Yangtze River were studied. The spatio-temporal evolution information of the islands was quantitatively extracted using the threshold value method, binarization model, and cluster analysis, based on Thematic Mapper (TM) and Enhanced Thematic Mapper+ (ETM+) images of the Landsat satellite series from 1985 to 2015. The variation mechanism and influencing factors were analyzed using an unstructured-grid, Finite-Volume Coastal Ocean Model (FVCOM) hydrodynamic numerical simulation, as well as the water-sediment data measured by hydrological stations. The annual average total area of these islands was 251,224.46 m2 during 1985–2015, and the total area first increased during 1985–2000 and decreased later during 2000–2015. Generally, the total area increased during these 30 years. Taipingzhou island had the largest area and the biggest changing rate, Xishadao island had the smallest area, and Zhongxinsha island had the smallest changing rate. The river islands’ area change was influenced by river runoff, sediment discharge, and precipitation, and sediment discharge proved to be the most significant natural factor in island evolution. River island evolution was also found to be affected by both runoff and oceanic tide. The difference in flow-field caused silting up in the Leigongdao Island and the head of Taipingzhou Island, and a serious reduction in the middle and tail of Taipingzhou Island. The method used in this paper has good applicability to river islands in other rivers around the world.

scholarly journals ICESat-2 Applications for Investigating Emerging Volcanoes

Geosciences ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 40
Author(s):  
Christine Simurda ◽  
Lori A. Magruder ◽  
Jonathan Markel ◽  
James B. Garvin ◽  
Daniel A. Slayback
Keyword(s):  
Remote Sensing ◽  
Satellite Remote Sensing ◽  
Laser Altimeter ◽  
Island Evolution ◽  
Novel Method ◽  
Island System ◽  
Volcanic Islands ◽  
Visible Imagery ◽  
Rare Opportunity ◽  
Recent Eruption

Submarine volcanism in shallow waters (<100 m), particularly in remote settings, is difficult to monitor quantitatively and, in the rare formation of islands, it is challenging to understand the rapid-paced erosion. However, these newly erupted volcanic islands become observable to airborne and/or satellite remote sensing instruments. NASA’s ICESat-2 satellite laser altimeter, combined with visible imagery (optical and microwave), provide a novel method of evaluating the elevation characteristics of newly emerged volcanoes and their subaerial eruption products. Niijima Fukutoku-Okanoba (NFO) is a submarine volcano 1300 km south of Tokyo (Ogasawara Archipelago of Japan) that periodically breaches the ocean surface to create new islands that are subsequently eroded. The recent eruption in August 2021 is a rare opportunity to investigate this island evolution using high-resolution satellite datasets with geodetic-quality ICESat-2 altimetry. Lansdat-8 and Planet imagery provide a qualitative analysis of the exposed volcanic deposits, while ICESat-2 products provide elevation profiles necessary to quantify the physical surface structures. This investigation determines an innovative application for ICESat-2 data in evaluating newly emerged islands and how the combination of satellite remote sensing (visible and lidar) to investigate these short-lived volcanic features can improve our understanding of the volcanic island system in ways not previously possible.

Finite Larmor-Radius Theory of Magnetic Island Evolution

2001 ◽  
Vol 87 (21) ◽  
Author(s):  
F. L. Waelbroeck ◽  
J. W. Connor ◽  
H. R. Wilson
Keyword(s):  
Larmor Radius ◽  
Magnetic Island ◽  
Finite Larmor Radius ◽  
Island Evolution

A new approach to study the long-term urban heat island evolution using time-dependent spectroscopy

Urban Climate ◽  
2021 ◽  
Vol 40 ◽  
pp. 101026
Author(s):  
Svetlana A. Varentsova ◽  
Mikhail I. Varentsov
Keyword(s):  
Urban Heat Island ◽  
Time Dependent ◽  
Heat Island ◽  
New Approach ◽  
Island Evolution ◽  
Urban Heat

Micro-scale tearing mode turbulence in the diffusion region during macro-scale evolution of turbulent reconnection

2021 ◽  
Author(s):  
Takuma Nakamura ◽  
Hiroshi Hasegawa ◽  
Tai Phan ◽  
Kevin Genestreti ◽  
Richard Denton ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Energy Conversion ◽  
Magnetic Reconnection ◽  
Diffusion Region ◽  
Electron Diffusion ◽  
Efficient Energy ◽  
Micro Scale ◽  
Island Evolution ◽  
Macro Scale ◽  
Scale Evolution

&lt;p&gt;Magnetic reconnection is a key fundamental process in collisionless plasmas that explosively converts magnetic energy to plasma kinetic and thermal energies through a change of magnetic field topology in an electron-scale central region called the electron diffusion region. Past simulations and observations demonstrated that this process causes efficient energy conversion through the formation of multiple macro-scale or micro-scale magnetic islands/flux ropes. However, how these different spatiotemporal scale phenomena are coupled is still poorly understood. In this study, to investigate the turbulent evolution of magnetic reconnection, we perform a new large-scale fully kinetic simulation of a thin current sheet considering a power-law spectrum of initial fluctuations in the magnetic field as frequently observed in the Earth&amp;#8217;s magnetotail. The simulation demonstrates that during a macro-scale evolution of turbulent reconnection, the merging of macro-scale islands results in reduction of the rate of reconnection as well as the aspect ratio of the electron diffusion region. This allows the repeated, quick formation of new electron-scale islands within the electron diffusion region, leading to an efficient energy cascade between macro- and micro-scales. The simulation also demonstrates that a strong electron acceleration/heating occurs during the micro-scale island evolution within the EDR. These new findings indicate the importance of non-steady features of the EDR to comprehensively understand the energy conversion and cascade processes in collisionless reconnection.&lt;/p&gt;

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