<div>The A1 poster incorporates 4 images of Australia taken from space by Earth observing satellites. The accompanying text briefly introduces sensors and the bands within the electromagnetic spectrum. The images include examples of both true and false colour and the diverse range of applications of satellite images such as tracking visible changes to the Earth’s surface like crop growth, bushfires, coastal changes and floods. Scientists, land and emergency managers use satellite images to analyse vegetation, surface water or human activities as well as evaluate natural&nbsp;hazards.</div>

The Coorong, a shallow coastal lagoon at the mouth of the Murray River, has had a significant decline in water quality over the last 15 years because of reduced freshwater inflows. Salinity has increased throughout the lagoon and currently ranges between 60 and 190 psu depending on the proximity to the Murray Mouth and the season. Although nutrient inflow has been negligible in recent years, the lagoon is considered euthrophic. This study aimed to identify the source of nutrients and the biogeochemical processes that transform them. The key findings were: 1. Groundwater discharge is likely to be an important nutrient source 2. Nitrogen appears to be the nutrient limiting primary production 3. Decomposition of organic matter in the sediments is highly seasonal with much higher rates in the summer.

The historical record reveals that at least five tsunamis generated by earthquakes and volcanic eruptions along the Sunda Arc have impacted the West Australian coast (1883, 1977, 1994, 2004 and 2006). We have documented the geomorphic effects of these tsunamis through collation of historical reports, collection of eyewitness accounts, analysis of pre- and post-tsunami satellite imagery and field investigations. These tsunamis had flow depths of less than 3 m, inundation distances of up to several hundred metres and a maximum recorded run-up height of 8 m. Geomorphic effects include off-shore and near-shore erosion and extensive vegetation damage. In some cases, vegetated foredunes were severely depleted or completely removed. Gullies and scour pockets up to 1.5 m deep were eroded into topographic highs during tsunami outflow. Eroded sediments were redeposited as sand sheets several centimetres thick. Isolated coral blocks and rocks with oysters attached (~50 cm A-axis) were deposited over coastal dunes however, boulder ridges were often unaffected by tsunami flow. The extent of inundation from the most recent tsunamis can be distinguished as strandlines of coral rubble and rafted vegetation. It is likely that these features are ephemeral and seasonal coastal processes will obscure all traces of these signatures within years to decades. Recently reported evidence for Holocene palaeotsunamis on the West Australian coast suggests significantly larger run-up and inundation than observed from the historical record. The evidence includes signatures such as chevron dunes that have not been observed from historical events. We have compared the geomorphic effects of historical tsunami with reported palaeotsunami evidence from Coral Bay, the Cape Range Peninsula and Port Samson. We conclude that much of the palaeotsunami evidence can be accounted for via more traditional geomorphic processes such as reef evolution, aeolian dune formation and archaeological site formation.

This report describes a detailed assessment of coastal vulnerability and infrastructure exposure undertaken for Mandurah local government area (LGA) to complement the analyses in the National Coastal Risk Assessment. The assessment modelled both storm surge and coastal recession. The hydrodynamic storm surge modelling conditions were based on those observed during TC Alby (1978) and included scenarios with the storm track shifted to create maximum impact of the wind field on Mandurah, and sea-level rise scenarios from 0.0 m (current climate) to 1.1 m. Potential shifts in the shoreline position were modelled based on changes in the sediment transport regime under sea-level rise. The resulting inundation from the modelled surge and erosion event was projected onto the coastline to give impact 'footprints' for each event. These footprints were overlaid with built asset data from Geoscience Australia's National Exposure Information System (NEXIS), as well as road, railway and bridge infrastructure. The storm modelling exposure analysis found that if the 1978 Tropical Cyclone Alby storm were to directly impact Mandurah LGA today then approximately 560 buildings are exposed to storm-tide inundation. This exposure increases to nearly 3,000 buildings when factoring in a rise in sea level of 1.1m by 2100. Within the area modelled to be potentially subject to erosion due to sea-level rise by 2030 there are between 140 and 800 buildings. However, by 2100 the range increases to between 2,300 and 4,100 buildings. This study has provided fundamental coastal process predictions that can better enable adaptation plans; and a benchmark of coastal vulnerability to inundation and erosion for the City of Mandurah against which the success of future adaptation initiatives can be measured. With refinements, the modelling methodology presented here is capable of being utilised across Australia to further quantify our coastal vulnerability.

Objectives 1. To determine the horizontal and vertical extent of hydrogen sulphide (H2S) in Lake Wollumboola sediments. 2. To examine controls on H2S gas production in Lake Wollumboola sediments. Activities 1. During a visit to Lake Wollumboola in November 2001, Geoscience Australia collected sediment samples, from sediment cores to depths of generally 180 mm, and occasionally to 600 mm. 2. The 12 sample sites chosen incorporate the three different sediment types of Lake Wollumboola; marine sands on the eastern side of the lake, central basin muds in the relatively deeper central part of the lake, and fluvial sands and muds on the western side of the lake where the creeks are depositing sediment from the catchment. 3. We measured H2S in sediment porewaters, immediately after sample collection. Porewater sulphate and chloride were measured in the laboratory. 4. Total sulphur, total iron, and total organic carbon were measured in the laboratories at Geoscience Australia, after the survey. Background Bacteria, which occur naturally in Lake Wollumboola's sediments, produce H2S when they breakdown organic matter. The bacteria, which are called sulphate reducing bacteria, utilise sulfate from the water to breakdown the organic matter, and can only operate under oxygen free (anoxic) conditions. Key Findings 1. H2S production in Lake Wollumboola is extensive. The average H2S concentration in the central basin muds and fluvial sands and muds is ~3000 M. At one site in the central basin muds, H2S concentration is greater than 10 000 M. In contrast, the concentration of H2S in the sandy marine sediments on the eastern side of the lake is low in comparison to the central basin muds and fluvial delta sands and muds. The average H2S concentration in the marine sands is 158 M. 2 Measurements of total organic carbon show that the amount of organic matter is higher in the central basin muds and fluvial delta sands and muds (~3.5 wt%) than in the marine sands (~0.8 wt%). Organic matter is the fuel for H2S production. High H2S concentrations in the central basin muds and fluvial delta sands and muds are probably a result of their high organic matter contents. 3. Depth profiles of H2S concentration and sulphate depletion in the central basin muds and fluvial sands and muds show that H2S production is occurring right at the sediment surface and down to depths of 80-100 mm. This implies that H2S could escape directly into the atmosphere, when the central basin muds and fluvial sands and muds are exposed during times of low lake levels. It also suggests that H2S could build up in the bottom layer of water directly above these sediments if the water remains anoxic for periods of time. 4. Total sulphide measurements show that H2S is reacting with iron in the sediments, forming iron sulphide minerals. Iron is an important trapping mechanism for H2S, preventing its escape to the atmosphere. Most sites, however, do not have enough `reactive iron' available and H2S concentrations are able to build-up in the porewaters of the sediment.

This dataset maps the geomorphic habitat environments (facies) for 15 Northern Territory coastal waterways. The classification system contains 9 easily identifiable and representative environments: Bedrock, Channel, Flood- and Ebb-tide Delta, Fluvial (bay-head) Delta, Intertidal Flats, Mangrove, Rocky Reef, Saltmarsh/Saltflat, Tidal Sand Banks (and Unassigned). These types represent habitats found across all coastal systems in Australia. Most of the 15 coastal waterways have a "Near Pristine" environmental condition (as opposed to "Modified"), according to the National Land and Water Resources Audit definition. Estuaries in the Northern Territory are predominantly tide-dominated barrier estuaries.

This dataset maps the geomorphic habitat environments (facies) for 85 Western Australia coastal waterways. The classification system contains 11 easily identifiable and representative environments: Barrier/back-barrier, Central basin, Channel, Coral, Flood- and Ebb-tide Delta, Fluvial (bay-head) Delta, Intertidal Flats, Mangrove, Rocky Reef, Saltmarsh/Saltflat, Tidal Sand Banks (and Unassigned). These types represent habitats found across all coastal systems in Australia. Western Australia has a diverse range of Estuaries due to different climates. Ranging from mostly "near pristine" and tide influenced estuaries in the north to "near pristine" wave dominated estuaries in the southwest region.

This dataset maps the geomorphic habitat environments (facies) for 140 Queensland coastal waterways. The classification system contains 12 easily identifiable and representative environments: Barrier/back-barrier, Bedrock, Central Basin, Channel, Coral, Flood- and Ebb-tide Delta, Fluvial (bay-head) Delta, Intertidal Flats, Mangrove, Rocky Reef, Saltmarsh/Saltflat, Tidal Sand Banks (and Unassigned). These types represent habitats found across all coastal systems in Australia. Most of the 140 coastal waterways have a "Near Pristine" environmental condition (as opposed to "Modified"). Southern and central Great Barrier Reef lagoon coasts have a broad spectrum of river, tide and wave- dominated estuaries.

This dataset maps the geomorphic habitat environments (facies) for 131 New South Wales coastal waterways. The classification system contains 12 easily identifiable and representative environments: Barrier/back-barrier, Bedrock, Central Basin, Channel, Coral, Flood- and Ebb-tide Delta, Fluvial (bay-head) Delta, Intertidal Flats, Mangrove, Rocky Reef, Saltmarsh/Saltflat, Tidal Sand Banks (and Unassigned). These types represent habitats found across all coastal systems in Australia. Most of the estuaries of New South Wales are under intense land use pressure with approximately 80% of the State's population living near an estuary (NSW Dept of Land and Water Conservation) .

Benthic nutrient fluxes from the sediments were measured at three Sites in the Bombah Broadwater of Myall Lakes during the winter (June) of 2000. Surface sediments (0-1 cm) and two cores were collected at each site and processed for measurements of carbon and nitrogen isotopic composition of the OM (organic matter), biomarkers and bulk sediment composition (OM and major cations). Pore waters were extracted from sediments and measured for both organic and inorganic metabolites. Biomarker, benthic flux data and the compositions of inorganic metabolites in pore waters indicated that Redfield OM (organic matter) was predominant in the sediments and mostly diatomaceous and probably responsible for the observed release of nutrients from the sediments to t he overlying waters. Carbon degradation rates in the sediments, during these winter month, varied between 5-47 mmol m-2 d-1 (60-564 µg m-2d-1) and were highest in the muddy sediments (mean = 21.3 +/-12.7 mmol m-2 d-1) as compared to the sandy sediments (mean = 11.6 +/-4.8 mmol m-2 d-1). DIN fluxes were less than those predicted from CO2 fluxes and Redfield stoichiometry and the `missing nitrogen' (subsequently determined by mass spectrometry as N2) was indicative of denitrification in the surface sediments. Rates of denitrification calculated from N2 directly and from `missing N' were similar and up to 5.1 mmol N m-2 d-1. There was no evidence of organic metabolite fluxes although the organic and inorganic metabolite concentrations were similar in the pore waters. Denitrification efficiencies were high (mean = 80 +/- 4%) in the sandy sediments and lower (although there was considerable variability) in the muddy sediments (mean =38% +/- 9%). Most DIP (generally > 70%) liberated to pore waters during OM degradation was not released into overlying waters but remained trapped and enriched in surface sediments. Benthic nutrient fluxes (average DIN/DIP = 131) were preferentially enriched in N compared to the OM (N/P = 16) raining into the sediments. Adjective biophysical processes (not diffusive) dominated the fluxes of metabolites across the sediment -water interface.