This one-page document, providing information about the Modified Mercalli Intensity (MMI) scale in table form, is replicated from the USGS https://earthquake.usgs.gov/learn/topics/mercalli.php. NEAC ShakeMap and FeltGrid products are rendered on the Earthquakes@GA website (https://earthquakes.ga.gov.au) using the MMI scale presented here. This 'About MMI' document can also be accessed through the Earthquakes@GA website, via the 'ShakeMap, FeltGrid and other downloads' listing for each earthquake under the 'Recent Earthquakes' menu.

<div>The 22nd September 2021 (AEST) <em>M</em>W 5.9 Woods Point earthquake in the Victorian High Country was the largest onshore event to have occurred in Victoria in the modern instrumental era, and probably since European settlement. Geoscience Australia’s National Earthquake Alerts Centre (NEAC) received in excess of 43,000 felt reports from the Australian community, with peak rates of almost 700 reports per minute.&nbsp;The felt reports ranged in severity from personal alarm to building damage. These crowd-sourced felt reports are received by Geoscience Australia in real time and mapped on the publicly available EQ@GA website. Other studies showed that felt reports alone can be used to estimate the potential impact of the earthquake in its early stages. The number and the spatial extent of felt reports are easily visible on the website, and the ShakeMap and FeltGrid features show the modelled and reported intensity as the reports are being received. These sources of information can help support emergency managers in making decisions for coordinated response. <b>Citation:</b> Pejic, T., Allen, T.I.; Crowd-sourced Felt Reports for 22 September 2021 MW 5.9 Woods Point earthquake: actions of the public; <i>AJEM</i> 39:2, April 2024, pp 51-56.

This product is a one-page description of the National Earthquake Alert Centres' "FeltGrid" product. A FeltGrid is produced for any earthquake for which NEAC receives a sufficient number of community reports of shaking intensity (aka 'felt reports), via the Earthquakes@GA website (https://earthquakes.ga.gov.au). The felt reports are converted to Modified Mercalli Intensity (MMI) scale, and translated into a map of average reported shaking intensity rendered at pre-set spatial scales on Earthquakes@GA. This 'About FeltGrid' document can also be accessed through the Earthquakes@GA website, via the 'ShakeMap, FeltGrid and other downloads' listing for each earthquake under the 'Recent Earthquakes' menu.

This one-page document provides general information about Geoscience Australia's ShakeMap. From December 2019, ShakeMap products will be available from GA's earthquake's website (https://earthquakes.ga.gov.au) for Australian earthquakes magnitude MLa 3.5 and above. This 'About ShakeMap' document can also be accessed through the Earthquakes@GA website, via the 'ShakeMap, FeltGrid and other downloads' listing for each earthquake under the 'Recent Earthquakes' menu.