Geoscience Australia carried out a marine survey on Lord Howe Island shelf (NSW) in 2008 (SS062008) to map seabed bathymetry and characterise benthic environments through colocated sampling of surface sediments and infauna, rock coring, observation of benthic habitats using underwater towed video, and measurement of ocean tides and wavegenerated currents. Subbottom profile data was also collected to map sediment thickness and shelf stratigraphy. Data and samples were acquired using the National Facility Research Vessel Southern Surveyor. Bathymetric data from this survey was merged with other preexisting bathymetric data (including LADS) to generate a grid covering 1034 sq km. As part of a separate Geoscience Australia survey in 2007 (TAN0713), an oceanographic mooring was deployed on the northern edge of Lord Howe Island shelf. The mooring was recovered during the 2008 survey following a 6 month deployment. lh_4m is an ArcInfo grid of the Lord Howe survey area produced from the processed EM300 bathymetry data of the survey area using the CARIS HIPS and SIPS software.

grid dataset, 250m pixel size, from contours

Hillshade (315°/45°) of the New Zealand Regional Bathymetry grid 2008

Slope in ° from the New Zealand Regional Bathymetry 2008 grid, generated using ArcGIS Spatial Analyst

Predicted seafloor topography of the New Zealand region: a nonlinear least-squares inversion of satellite altimetry data (2000) * Ramillien, G., * Wright, I.C. Abstract We use a nonlinear least squares inversion to derive predicted seafloor topography (hereinafter referred to as RW99) for the New Zealand region (146°E–165°W, 60°S–25°S), combining altimetry data from ERS-1 and Geosat Geodetic Missions, as well as available shipborne gravity and echo sounding data. Currently, the lithospheric component of the model is principally applicable to thinly sedimented oceanic basins; however, we have attempted, though with only partial success, to compensate for regional crustal variations. The upper part of the oceanic lithosphere has an elastic behavior related to a half-space cooling model and flexing under seafloor relief load. Using least squares theory, the topographic solution is derived as a linear combination of altimetry and in situ measurements with adjusted coefficients. These coefficients are iteratively fitted using nonlinear operators between bathymetry and altimetry-derived gravity anomalies assuming their error distributions are Gaussian. The theory enables sparse in situ data to be included in the inversion, such as depth soundings and marine gravity profiles. In comparison with the global model of Smith and Sandwell [1997] (hereinafter referred to as SS97), the RW99 predicted topography is constrained by over threefold more shipborne soundings data and the inclusion of shipborne gravity data. Three strategies are used to validate the RW99 model. Compared to the root-mean-square (rms) error of 310 m of the SS97 model, final residual differences for the RW99 model are within the range of 104–250 m. These rms errors are the result of uncertainties of model parameters, especially the elastic thickness and the relief density, but also the complexity of seafloor topography. In addition, the model inversion does not presently consider gravitational contributions of marine sediments of variable thickness.

Actual evaporation is an estimated average annual value for 1960-2006. The values are calculated using AE = PE .* ( 1 + P/PE - (1+ (P/PE)^w)^(1./w) )whereAE = average annual actual evaporationPE = average annual potential evaporation (item 2 above)P = average annual precipitation (item 1 above)W = 4.35 (empirical constant value)

Smith & Sandwell predicted seafloor topography. http://www.sciencemag.org/content/vol277/issue5334/ http://topex.ucsd.edu/WWW_html/mar_topo.html

Potential evaporation is average annual Penman Potential Evapotranspiration for 1960-2006. It is interpolated from the potential evaporation data calculated at climate stations.