Category Archives: Sea Level

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

Florida Bay islands grow in size

“Instead of inundation from sea level rise, 80% of assessed Florida Bay (USA) islands grew in area during 1953-2014, prototyping a global-scale trend in island resistance to rising seas.” click here

Basic science: sea-level rise is cyclical, not catastrophic

“In this paper, basic science is used to show that catastrophic SLR from melting ice cannot happen naturally over a short period. Additionally, humankind does not possess the capability to melt a large amount of ice quickly even through our most advanced technology. This news should relieve the public, which is routinely deceived by reporting that misrepresents the facts. The public is susceptible to unnecessary alarmism when melt rates and ice-melt masses are presented without perspective and juxtaposed against claims that scientists are worried. This paper uses the same facts but places them in perspective to show that catastrophic risks do not exist.” click here

Palo Alto, CA sea-level rise fears are not science-based

“One minor problem with the experts claim though, is that it has no basis in science or reality. Had these experts done any actual research, they would have known that sea level in the San Francisco Bay is almost exactly the same as it was in 1940.” click here