Significant local sea level variations caused by continental hydrology
signals
- Rebecca McGirr,
- Paul Tregoning,
- Anthony Patrick Purcell,
- Herbert W. S. McQueen
Abstract
Space gravity missions have enabled the quantification of ocean mass
increase over the past two decades due to exchanges between continents
and oceans. Globally, non-steric sea level rise is predominantly driven
by melting polar ice sheets and mountain glaciers. However, continental
hydrological processes also contribute to sea level change at
significant magnitudes. We show that for most coastal areas in
low-to-mid latitudes, up to half of local non-steric sea level rise is
due to changes in water storage in ice-free continental regions. At
other locations the direct attraction effect of anthropogenic pumping of
groundwater over the duration of the GRACE and GRACE-FO mission offsets
sea level rise from ice sheet and glacier melt. If these trends in
continental hydrological storage were to slow or stop, these regions
would experience greatly accelerated sea-level rise, posing a risk to
coastal settlements and infrastructure, however, sea level rise
elsewhere would be reduced.