https://ogma.newcastle.edu.au/vital/access/ /manager/Index ${session.getAttribute("locale")} 5 https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:35813 Thu 05 Dec 2019 15:27:11 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:51959 550 km) from CubeSat GPS tracking data. The satellite sampling along many CubeSat orbits enable to map broader spatio-temporal patterns of the TID propagation compared to ground receivers. Due to the larger spatial coverage over a shorter period of time, the CubeSat measurements provide complementary information to stationary ground receivers. We found that the amplitude of the HTHH-induced ionospheric perturbations at high altitudes (>550 km) are as large as 10 TECU (1 TECU = 1016 electrons/m2) in slant total electron content between CubeSats and GPS satellites. The TIDs traveled along with the Lamb waves and were recorded by CubeSats above India 12 hr after the eruption and at the antipode of the eruption 16 hr after. These suggest that the ionospheric disturbances reached to the high altitudes and traveled globally as a speed of ∼350 m/s. The TIDs were also detected by CubeSats above the Australian continent several hours before the (conventional) tsunami made landfall on the Australian coasts. We discuss a new opportunity to study the upper ionosphere and its coupling with the solid Earth and to develop advanced monitoring systems of geohazards by the advent of low-cost small satellite technology.]]> Fri 22 Sep 2023 17:04:28 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:40035 2. There is good agreement between GRACE measurements and tsunami models for the three events. Complementarily to buoys, ocean bottom pressure sounders, and satellite altimeters, GRACE is sensitive to the long-wavelength spatial scale of tsunamis and provides an independent source of information for assessing alternate early earthquake and tsunami models. Our study demonstrates an innovative way of applying GRACE and GRACE Follow-On data to detect transient geophysical mass changes which cannot be observed by the conventional monthly Level-2 and mascon solutions.]]> Fri 15 Jul 2022 10:11:21 AEST ]]>