Category Archives: Sea Level

Separating truth from error regarding sea level change

Fears of apocalyptic sea-level rise unwarranted

“Fears of apocalyptic sea-level rise are nothing new despite the fact that they seem to have recently taken on a new life of their own, especially in South Florida, where I live.

The only scientific correlation I can make with any certainty is that these fears rise in direct proportion to the number of socialists elected to Congress.” click here

Reef islands (e.g. Tuvalu) respond naturally to sea-level changes

Megan E. Tuck, Paul S. Kench, Murray R. Ford, Gerd Masselink. Physical modelling of the response of reef islands to sea-level rise. Geology (2019), https://doi.org/10.1130/G46362.1

“Sea-level rise and increased storminess are expected to destabilize low-lying reef islands formed on coral reef platforms, and increased flooding is expected to render them uninhabitable within the coming decades. Such projections are founded on the assumption that islands are geologically static landforms that will simply drown as sea-level rises. Here, we present evidence from physical model experiments of a reef island that demonstrates islands have the capability to morphodynamically respond to rising sea level through island accretion. Challenging outputs from existing models based on the assumption that islands are geomorphologically inert, results demonstrate that islands not only move laterally on reef platforms, but overwash processes provide a mechanism to build and maintain the freeboard of islands above sea level. Implications of island building are profound, as it will offset existing scenarios of dramatic increases in island flooding. Future predictive models must include the morphodynamic behavior of islands to better resolve flood impacts and future island vulnerability.” click here

For more discussion click here.

Sinking in Seattle, sea-level rise minor

Sergey V. Samsonov, Kristy F. Tiampo, Wanpeng Feng. Fast subsidence in downtown of Seattle observed with satellite radar, Remote Sensing Applications: Society and Environment, Volume 4, October 2016, Pages 179-187

Abrupt change in the long term displacement trend was observed in the downtown of Seattle (Washington, USA) with the satellite Differential Interferometric Synthetic Aperture Radar (DInSAR). The forty nine ascending and forty six descending RADARSAT-2 Spotlight SAR images with range-azimuth resolution of 1.6×0.8 m and ground coverage of 18×8 km were collected during June 6, 2012–August 16, 2015. The vertical deformation time series were computed from the ascending and descending data sets with the advanced Multidimensional Small Baseline Subset (MSBAS) software. During June 6, 2012–August 31, 2014 subsidence occurred along the two transportation routes, running north-south parallel to the coast line, reaching 2.5 cm. The long term deformation rate did not exceed 1.2 cm/year and was nearly constant during that time. After August 31, 2014, rapid subsidence appeared in the downtown of Seattle, in a region where it previously was not observed. Over the next four months during August 31, 2014–December 29, 2014 cumulative subsidence reached approximately 2.5 cm, which corresponds to an annual rate of 10 cm/year, about eight times faster than during the previous two years. The rate of subsidence remained high for an additional few months before converging to its secular value. The cause of subsidence was linked to the recent anthropogenic activities related to tunnel boring for Alaskan Way Viaduct replacement project. The elliptical model for subsidence due to groundwater pumping proposed by Tiampo et al. (2012) was used to invert for the physical parameters of the associated groundwater pumping. The results are in good accordance with the location of pumping operations and the groundwater bearing strata in the region. Over a long period of time such fast subsidence will cause additional strain on urban infrastructure, particularly older, historic structures and high-rise buildings. This work provides an excellent example of the importance and applicability of rapid, accurate monitoring of ongoing, large infrastructure projects using DInSAR techniques in order to make optimal use of limited resources and perform early intervention and mitigation strategies.

LA Times publishes fake news about sea-level rise

 

Tuvalu and most Pacific islands have grown in size. They are not sinking into the sea.

“TIME titled it’s Thursday cover story, “Our Sinking Planet.” There’s just one problem: Scientific studies show Tavalu’s islands, indeed most Pacific islands, have actually grown in the face of sea level rise.” click here

Global sea-level rise: an evaluation of the data

“Burton (2018) reports the highest quality coastal tide gauges from around the world show no evidence of acceleration since the 1920s or before, and therefore no evidence of being affected by rising atmospheric CO2 levels.” click here