disaster medical aspects for Melbourne

see also:

Introduction

Melbourne is relatively fortunate it is itself in a fairly low risk region for natural disasters with the most frequent events being:
- bushfires and grassfires are common events but are generally confined to more rural areas and Melbourne itself is unlikely to be directly impacted but the smoke can cause serious impacts to air quality
- a local severe storm can cause prolonged power outages to a number of suburbs, especially those with many tall trees and overhead powerlines as occurred in the Dandenongs
- riverine flooding can affect the Maribyrnong River areas in particular
- flash flooding during severe rain storm events can cause serious but usually transient local flooding events
- heat waves
less common but potentially high consequence events include:
- cyber-terrorism is a far more likely major disaster scenario as this could cause a range of events including a prolonged power outage
- aircraft crash into populous areas
- fortunately severe earthquakes or tornadoes are rare but are a risk
- there has not been a volcano for over 5000 years and this remains extremely unlikely
- another human pandemic is reasonably likely, especially given the state of the bird flu pandemic
- war is of increasing risk but thankfully Melbourne is quite remote from any likely war regions - nevertheless, war is likely to rage using cyber security issues, which could easily impact Melbourne
sea level rise from climate change is likely to impact low lying coastal areas such as Elwood and parts of Port Melbourne especially in the next 50-100 years

the rarity of major disasters means Melbournians are generally very complacent when it comes to disaster preparedness and contingency planning
- a large proportion would be at risk of being under-prepared in a major event with little or no contingencies and almost complete reliance upon State support
- thanks to Covid-19 lockdowns, many Melbournians now have significant camping gear or caravans which may be of use in certain disasters

Melbourne's electrical power supplies

see https://openinframap.org/#6.87/-37.306/145.406 for map of Melbourne's power infrastructure
base load supplies
- mainly from coal powered stations located in the Latrobe Valley, Gippsland, some of these have been closed down recently and this risks the need for local “brown outs” in peak high demand especially during heat waves when air conditioner demand is very high
- Snowy Hydro Scheme in northeast Victoria is an important source of electricity for Melbourne, providing both base load and peaking power
- gas powered stations such as at Newport provide additional power
- small hydro-electric plants at several of Melbourne's reservoirs
renewable sources for peak load supports
- wind farms (mainly in SW Vic and offshore)
- solar (mainly near NSW border, especially near Ouyen, and residential)
  - https://mapshare.vic.gov.au/planningwebmaps/RenewablesSummary.html
battery storage systems
- these are being built to improve reliability of renewable sources and reduce reliance on coal-powered stations
- Victoria has installed and activated Australia’s largest lithium-ion battery at the 300MW Tesla Moorabool Terminal Station, just outside Geelong and can store enough energy to power more than one million Victorian homes for 30 minutes
  - operates as a virtual transmission line between November and March each year. It enables increased flows of up to 250 MW over the Victoria-New South Wales interconnector. This reduces the risk of unscheduled load shedding during summer.¹⁾
- Ballarat Energy Storage System 30MW/30MWh
- Gannawarra Energy Storage System 25MW/50MWh
transmission systems
- electricity is delivered to Melbourne through the National Electricity Market (NEM), one of the world’s largest interconnected power systems, which links Victoria with other eastern and southern states.
- these are a risk for starting bushfires in strong winds during extreme heat conditions
- these are at risk of local failure in extreme wind events either from buckling or fallen power line structures, or from damage from falling trees

Melbourne's water supplies

these are a series of mainly interconnected gravity fed storages from closed catchments east of Melbourne, several with small hydro-electric plants
- the 1068GL Thomson Reservoir is the largest, highest and most distant one and feeds into the 200GL Upper Yarra Reservoir which along with O'Shannassey Reservoir, feeds into the O'Shannassey Aqueduct and into the off-stream 40GL Silvan Reservoir
  - the Silvan Reservoir then sends feeds to the north (27GL Greenvale Reservoir), east and south to the 287GL Cardinia Reservoir
- the 22GL closed catchment Maroondah Reservoir also feeds into the the 96GL Sugarloaf Reservoir which also has a feed from the Yarra River at Yering Gorge
- the oldest reservoir is the 30GL open catchment Yan Yean Reservoir in the north which receives a feed from the 2nd oldest reservoir, the closed catchment Toorourrong Reservoir.
- in the north-west, Rosslynne Reservoir provides water to Sunbury and Macedon Ranges area and supports irrigation and provides water to private diverters along the Maribyrnong River
- to the west, Merrimu Reservoir provides water to Bacchus Marsh and Melton while Pykes Creek Reservoir supplies Myrniong as well as Bacchus Marsh and Werribee Irrigation Districts.
- the Melbourne to Geelong Pipeline (MGP) is a 59km underground pipeline which can supply Geelong with water from Melbourne if needed to supplement its regional supplies
in severe drought, there are also two other contingencies which can be brought into play:
- the North South Pipeline can receive flows from the Goulburn River to the Sugarloaf Reservoir - “only be used in times of critical human need eg. total water storages < 30% capacity by 30th Nov of a year”
- the desalination plant in Gippsland which can feed into the Cardinia Reservoir
in addition to these there are local small storages which usually rely upon electrical pumping

Prolonged power outages

prolonged power outages are likely to have a major impact on Melbourne as with any region given modern systems are almost totally reliant upon electricity
currently most solar panel systems connected to the grid will be switched off if the grid goes down for safety reasons - a potential exception may be if they solar panels are connected to a local large battery system and can be isolated from the grid
hospitals and other key buildings generally have back up power generators but these are likely to fail after 96 hours or so unless more diesel can be delivered

home power backups will quickly become exhausted

most homes do not have any power backups
those with solar panels PLUS lithium battery storage systems PLUS the ability to run their solar panels when the grid is down (most do not have this functionality) will have the best chance of managing a prolonged outage
examples of temporary power sources
- each 100Ah 12V LiFePO4 camping battery provides ~1.2kWh capacity but could be recharged by camping solar panels off grid, or by a petrol or diesel power generator
- most “camping” petrol or diesel power generators can provide 1.8kW of continuous power using around 0.45L of petrol per 1kWh of output - how much fresh petrol will you have available as you probably won't be able to buy any?
- lithium battery storage system which does not have ability to be recharged during a grid power outage if the system shuts down the solar panels:
  - most residential systems have capacities of 9.6-16kWh which equates to 8-13 100Ah 12V LiFePO4 batteries or 5-8L of petrol
examples of appliance power loads
- air conditioners 2800W - would probably need two joined petrol generators to keep it running, if you could access the 15A power plug/direct wiring which is unlikely.
- portable electric heaters 1200-2400W - might be able to be ran on one petrol generator to keep one room warm
- kettle 2200W - boiling 0.5L water at 2200W takes 1.5 minutes and uses 58Wh = 11Wh per 100mL water boiled
- induction stove
  - kitchen induction stove on max can boil 500mL water in 70secs
  - single standalone unit 200-2000W depending on setting, but usually need at least 600-800W for most heating tasks
    - example: portable 2000W Kickass induction stove:
      - boiling 500mL water at “400W” on cycles between 1160W (4.8A AC ~100A 12V DC), 450-600W and 4W taking 8.5min and using around 57Wh
      - boiling 500mL water at “2000W” on portable 2000W Kickass induction stove maintains relatively constant 1890W taking 100sec and presumably using around 55Wh
      - without a full AC power backup system, you would as a minimum need a well charged premium LiFePO4 battery of at least 100A max discharge rate (preferably higher), an AC Inverter 1200-2000W directly connected to the battery with heavy duty cables (Anderson plugs are only rated to 50A) - if the current draw causes the battery voltage to drop below its minimum (usually around 11.9V), the battery will cut out - you may be better off using a 800W rated induction stove!
- inverter microwave 1000-1100W
  - boiling 500mL water at 1100W with inverter microwave seems to be less efficient than kettle or induction stove and takes about 4 minutes = 70Wh
  - reheating a single meal will consume approx. 25Wh
- gas heater wall furnaces - uses ~40W for the fan
- laptops often use 65W

to run AC appliances from a DC source such as a lithium battery, you will need a suitably rated AC inverter but note, running a 1000W appliance will exhaust a 100Ah 12V battery in about 1 hour of use
- portable camping solar panels are generally rated to provide 100-300W output in ideal conditions

gas supplies to houses should be retained unless the gas pipeline infrastructure is damaged such as in an earthquake
- unfortunately, most, if not all, home gas appliances or portable diesel heaters require electricity to run, so you will need a battery and AC inverter for this, but usually the power consumption is quite low so this would be sustainable for a while
- new houses in Victoria will NOT have a gas supply connection as gas availability is falling
- in 2026, piped gas supplies to 10 regional towns will end (Robinvale, Swan Hill, Kerang, Nathalia, Marong, Maldon, Heathcote, Terang, Lakes Entrance and Orbost) as Solstice Energy has announced in 2025 it will phase out its compressed natural gas (CNG) networks
some houses have wood heaters however supply of wood may not last long in urban areas
- a better, more wood efficient option would be wood camping stoves with chimneys which could be used outside or in tents (with ventilation)
many people may resort to using very high carbon monoxide producers indoors which will be lethal - eg. heat bead products

food refrigeration failure

this is likely to occur early and significantly impact food supplies
a camping LiFePO4 battery with AC inverter and a solar panel may be able to avert this issue in the home fridge at least for a few days and possibly longer but retail supplies of these foods are likely to become scarce
people will need to rely upon foods that do not require refrigeration such as canned foods, most vegetables, fruits and nuts

heating and cooling failures

these could have major impacts in extremes of weather
even gas heaters generally need electricity to function

communication failures

mobile phone and internet services are likely to fail
access to information will be difficult
portable AM/FM radios will be useful

transportation failures

trains and trams will fail immediately
airports are likely to be closed
electric vehicles will soon run out of electricity
petrol and diesel vehicles may be able to continue but there is likely to be issues with obtaining fuel:
- credit cards will not work so cash will be needed
- fuel station pumps usually need electricity to work

commerce failures

loss of banking / credit card systems will mean purchases will need to be made with cash
very few have large enough amounts of cash in their houses to manage this adequately
this will then impact ability to buy fuel and food

emergency services failures

communication systems failures will impact emergency services who will need to rely upon portable radio devices

security system failures

these are likely to fail once local battery backup systems are exhausted

civil unrest

looting is likely to become common

sewerage systems

sewerage systems need electricity to ensure the sewage is continually pumped to treatment plants
various mitigation systems are in place such as:
- most major sewage pumping stations and treatment plants, such as the Eastern Treatment Plant (ETP), have backup power systems, including biogas-powered generators and multiple high-voltage electricity feeders to ensure continued operation during short-term outages
- for local systems, such as pressure sewer units serving individual homes, there is emergency storage built in—enough to hold more than a day’s worth of wastewater.
however, these are likely to fail or be inadequate if there is a prolonged outage and this could result in:
- sewage backing up in pipes and potentially overflowing into streets or homes, especially in low-lying areas
- emergency storage in local systems filling up, after which manual pump-outs or portable generators would be required to prevent overflows
- increased risk of environmental contamination if untreated sewage is released and in addition to polluting waterways and the Port Phillip Bay, this increases the risk of major disease outbreaks of gastroenteritis, dysentery, hepatitis A, perhaps typhoid, and many other pathogenic diseases.

water supplies

fortunately, Melbourne’s water supply is gravity-fed from reservoirs for much of the distribution network, which can continue to supply water for a time during outages
however, water booster pumps are required for high-rise buildings, elevated suburbs, and during periods of peak demand
vulnerable areas to a prolonged power outage include:
- high rise buildings
- elevated suburbs such as parts of Doncaster, Balwyn, and Glen Waverley
- areas supplied by one of Melbourne's 38 smaller service reservoirs that store water for 1–2 days of supply
  - fringe suburbs and peri-urban communities may depend on local pumping stations to move water from these reservoirs or through the distribution network
- areas supplied by Greenvale Reservoir which receives treated water from Silvan and Winneke systems:
  - Western Suburbs & Sunbury/Melton
- areas supplied by pump from Cardinia Reservoir:
  - Mornington Peninsula and suburbs in the south-east (e.g., Cranbourne, Frankston, Dandenong)
- areas supplied by the Maroondah Reservoir and Yarra Glen Service Reservoir
  - Yarra Glen & Lower Yarra Valley
- Healesville - receives water from catchments without a major storage reservoir buffer, making it especially vulnerable to outages or water quality issues
home swimming pools cannot easily be made potable:
- electrical pump failure will soon result in the pools becoming cloudy and develop high levels of algal growths
- pools also contain disinfection by-products (DBPs) such as trihalomethanes (THMs) and chloramines, high salt content, and other toxins which make them unsafe to drink without complicated treatment
- options include:
  - solar powered reverse osmosis filtration systems
    - these generally need water pressure of 50 PSI to 80 PSI feed to the reverse osmosis and so need an electrical pump
    - requires a calcite vessel to neutralise the water for human consumption and showering
    - needs a large rain water tank in which to store the filtered water
    - the filters are expensive and require replacing
  - distillation systems (slow and use a lot of energy)

Hazardous material release

this is most likely to occur due to either:
- industrial fires
- severe storms
- flooding
- transport accidents whilst the material is being transported
- terrorist acts
- corporate acts - allowing drainage into streams, etc
- inadvertent exposure from renovations, demolishment works or soil works (eg. asbestos, historic heavy metal soil contaminations, etc)
- fire fighting (PFAS, etc although these are no longer employed)
- and, rarely, earthquakes

Earthquakes

although Melbourne is not located close to plate boundaries, severe intraplate earthquakes can still occur
- one of the largest earthquakes in history, the New Madrid Earthquake in 1812 was a series of intraplate earthquakes of magnitudes ranging up to 8.2.²⁾
- the maximum estimated earthquake near Melbourne based upon the various fault lines is under magnitude 8 ³⁾
various fault lines lie adjacent to Melbourne including the Selwyn Fault, Mornington Peninsula and Rowsley Fault in Bacchus Marsh
main concern arises from Melbourne's large population and a significant stock of older buildings, particularly unreinforced masonry structures and and non-structural components (like gas pipes and ceilings), which are more vulnerable to even moderate seismic shaking
- masonry structures are more brittle than concrete, steel or timber structures.
- unless a particularly old masonry structure has been adequately retrofitted with seismic detailing such as steel reinforcement, it would be vulnerable.
- 16% of Melbournians live in high quake risk 1-3 storey high residences with unreinforced masonry bearing walls ⁴⁾
- in Melbourne, soft soils significantly enhance the action of an earthquake
- the structural capacity of shorter buildings is much less than that of more highly specified high-rise buildings, as they tend to be more rigid. As a result, low-rise buildings are generally at a higher risk of failure in an earthquake.⁵⁾
- the first seismic structural design code in Australia was introduced in 1979, whilst earthquake-resistant design was basically not exercised until the 1989 Newcastle Earthquake. The Australian Standard for earthquake action was then revised in 1993, and enforced in 1995. However it was not mandated and required for all commercial buildings until around 2008, following the 2007 release of the Australian Standard on earthquake actions, AS 1170.4 ⁶⁾
to date, Melbourne has not suffered catastrophic earthquake damage
- a magnitude 5.9 event in 2021 caused building damage despite its epicentre being 125 km away
the 5.6 magnitude 1989 Newcastle earthquake in NSW was very destructive and an event similar to this could occur in Melbourne
risk of a significant damaging event affecting Melbourne is rated at ~2% in the next 50 years
the frequency of earthquakes killing more than 1000 people in Greater Melbourne has been estimated to be 0.1% per annum at 5% over 50yrs, although this is higher than the stated risk a significant damaging event of 2% over 50yrs ⁷⁾
the highest risk in Victoria is in far eastern suburbs of Melbourne and west Gippsland from Yarra Junction southwards to Wilsons Prom with risk rated at ~10% in the next 50 yrs ⁸⁾
a magnitude 7.7 earthquake occurring at the Selwyn fault is estimated to have a 4.5% mortality rate for those living in residences with unreinforced masonry bearing walls ⁹⁾
a magnitude 7.8 event occurring at the Muckleford fault (near Castlemaine) would severely impact the Bacchus Marsh-Melton region in particular and this could include Rosslyn and Merrimu Reservoirs¹⁰⁾
severe earthquakes may cause:
- building damage and collapse - injuries are mainly from objects including walls or ceilings falling onto people
- older bridge damage and collapse
- gas pipe ruptures and fires
- water pipe ruptures - local flooding, disruption to water supply
- power failure
- release of hazardous materials
- tsunamis (distant quakes are unlikely to cause a tsunami affecting Melbourne - the east coast of Australia is at much greater risk of these)
- landslides (mainly an issue in the Dandenongs, Kinglake, etc)
- dam wall failure (very unlikely)
- heart attacks / stress events

Water storage major dam failures

It is very unlikely that a well constructed and maintained dam would fail.¹¹⁾
dam failures may occur due to either:
- earthquakes - most of the dams are in Victoria's highest risk earthquake zone (see above)
- major flood events causing prolonged over-topping
- poor construction or internal erosion of dam wall structure
- terrorism acts
flooding associated with dam failure would depend on the height of the dam wall, the amount of water in the dam and the shape of the valley below the dam
the path of water during the flood can also be difficult to predict as erosion or blockages by debris can change the course of the flood.
these are very unlikely
- the biggest dam supplying Melbourne, Thomson dam failure would not flood Melbourne but would possibly hit Heyfield and Sale
- Eildon dam failure would impact the Goulburn River system in central northern Victoria but not Melbourne
- Upper Yarra dam failure could potentially flood Melbourne as this flows into the Yarra River, impacting Warburton, Yarra Glen, Warrandyte and downstream to Melbourne
- Maroondah dam failure would flow into Watts River impacting Healesville before flowing into the Yarra
- Sugarloaf dam failure would also flow into the Yarra via Sugarloaf and Watsons Creeks
- Silvan dam failure would flow into Olinda Creek impacting Lilydale before flowing into the Yarra
- Yan Yean dam failure would flow into the Plenty River and impact the northern suburbs then flow through Greensborough and into the Yarra above Heidelberg
- Cardinia dam failure would flow into Cardinia Creek which flows SW through Beaconsfield and eventually to Westernport Bay via drains
- Rosslyn dam failure flows into Jackson Creek impacting Gisborne, Sunbury, Organ Pipes and then into the Maribyrnong River with impacts especially in Maribyrnong and Flemington
  - NB. the other main tributary into the Maribyrnong is Deep Creek which passes down from Cobaw ranges through Romsey but does not have any large reservoirs, although the Maribyrnong river itself is subject to reasonally frequent substantive riverine flooding
- Merrimu dam failure NW of Melbourne flows into Cockatoo and Pyrites Creeks southwards into the Werribee River which could impact Exford, and Werribee
- Pykes Creek dam failure W of Melbourne flows into Korjamnunnip Creek then into the Werribee River as above

Water storage contamination

this may be due to:
- natural causes (most likely only affecting one water source)
  - major flood events
  - land slides
  - major bushfires
  - toxic algae formation
  - gastro-intestinal pathogens such as cryptosporidium
  - heavy metal or other toxin contamination from newly exposed soil and rain runoff into dam following major bushfires, etc
- acts of terrorism
- failure of water supply quality management

Large scale toxic algae outbreaks

in 2025, a large scale outbreak in the ocean waters in Sth Australia including up to Adelaide has had prolonged and spreading impacts on fishing, swimming and had major deaths of many marine species
such an event could occur in Port Philip Bay
prolonged inhalation of toxins from sea spray could have long term as well as acute health risks
- living near inland water storages with toxic algae has been associated with increased risk of later development of motor neurone disease (MND) although causal effect not proven

Prolonged heat waves

heat waves are relatively common in Summer in Melbourne and do cause a substantial number of excess deaths in the community
these also place substantive pressures on Melbourne's peak electricity capacities and regional “brown outs” are likely with loss of air conditioning and refrigeration which exacerbate the heat wave conditions
- this may be partly mitigated with increased uptake of domestic solar systems with storage batteries
climate change may increase the frequency and severity of such events

Prolonged drought

Melbourne experienced a very severe and prolonged drought starting in the 1990's which not only resulted in major bushfires but it prompted the Victorian Govt to built a large desalination plant in Gippsland which has not been needed as the drought broke before it was completed, however, this remains an important backup option in addition to the numerous water reservoirs which supply Melbourne's water.
Climate change may increase the frequency and severity of such events

Space weather - geomagnetic risks

a very severe solar storm may cause loss of electrical and telecommunications networks - these events are historically uncommon

Failure or errors of global navigation satellite systems (GNSS)

these can be due to:
- very severe solar storms (see above)
- changes to Earth's magnetic field may result in erroneous compass or geolocation readings
  - the position of the magnetic poles is constantly changing
  - a different GNSS may use a different pole coordinate
- cyberterrorism - satellites generally have weak security systems which make them vulnerable to radio hackers
- State-based decisions to close a State-owned GNSS for a region or globally
  - this risk has been reduced now that there are several State owned GNSS available to receive data from (US GPS, Chinese BeiDou, Russian GLONASS, European Galileo)
- asteroid impacts on moon releasing massive amounts of dust into space (may happen Dec 2032)
this could have major impacts and cause major collisions, especially with flights, autonomous driven vehicles, etc.

Tsunami risk

Melbourne has a medium risk of a significant tsunami (10% chance of damaging event in 50 years) and much lower than most other regions thanks to the coastline facing south which is away from most severe earthquakes in the Pacific, and with the added protection of Port Phillip Bay, although a small tsunami from a local earthquake is possible
- see https://www.ga.gov.au/scientific-topics/community-safety/projects/ptha
- the highest risks of severe tsunami events in Australia are NW coastline of WA and Sunshine Coast in Qld down to Eden on the east coast of Australia
tsunamis may impact the Victorian coastline, especially eastern Victoria from Puysegur Trench (south of New Zealand and would have an impact time of 2 hrs after event), while a small tsunami hit from a magnitude 9.5 earthquake in Chile in 1960
no significant tsunami has impacted Melbourne in recorded history

Volcanic eruption

this is extremely unlikely as all Victoria's volcanoes have been dormant for over 5000 yrs but nevertheless an eruption is possible but most likely in SW Victoria rather than Melbourne
nevertheless, melting of glaciers and ice caps risks increasing volcanic activity with western Antarctica the highest risk

Collapse of Antarctic sea ice

Antarctica stores more than 90 per cent of the planet’s land-based fresh water
this process started in 2014 and appears to be accelerating and is at double the rate of loss as for the Arctic and causing self-perpetuating processes
- loss of ice and more sea water means less heat reflection back into space and more absorption further warming the region
- reduced Antarctic Overturning Circulation deep see current resulting in warm water staying on the surface longer, intensifying weather patterns, while reducing the carbon sink process where carbon is circulated from the surface down to the depths, and further impacts include nutrients on the sea floor fail to come to the surface where marine organisms depend on them
this will thus result in:
- rising sea levels that will impact coastal communities
- a warmer and deoxygenated Southern Ocean being less able to remove carbon dioxide from the atmosphere, leading to more intense warming in Australia and beyond bringing both droughts and floods
- increased regional warming from Antarctic sea ice loss
- reduced marine life with severe impacts on penguins, plankton, and fish

Supernova explosion

this is ZERO risk (unlike 41,000 yrs ago when a supernova may have impacted mammoths, or perhaps another one 13,000 yrs ago which may have ended the megafauna)
there are no stars likely to go supernova in the next 1000 years within the 250 light year distance that would impact life or the environment
the closest likely supernova is Betelgeuse which is a safe 400-600 light years away

¹⁾

https://www.energy.vic.gov.au/renewable-energy/batteries-energy-storage-projects/victorian-big-battery

²⁾ , ⁵⁾

https://pursuit.unimelb.edu.au/articles/what-victoria-s-earthquake-tells-us-about-the-safety-of-our-structures

³⁾ , ⁴⁾ , ⁶⁾ , ⁷⁾ , ⁹⁾ , ¹⁰⁾

https://aees.org.au/wp-content/uploads/2019/12/63-Hing-Ho-Tsang.pdf

⁸⁾

https://www.thinkhazard.org/en/report/5431-australia-victoria-yarra-ranges-s/EQ

¹¹⁾

https://www.water.vic.gov.au/__data/assets/pdf_file/0024/671532/dams-factsheet.pdf

Table of Contents

disaster medical aspects for Melbourne

Introduction

Melbourne's electrical power supplies

Melbourne's water supplies

Prolonged power outages

home power backups will quickly become exhausted

food refrigeration failure

heating and cooling failures

communication failures

transportation failures

commerce failures

emergency services failures

security system failures

civil unrest

sewerage systems

water supplies

Hazardous material release

Earthquakes

Water storage major dam failures

Water storage contamination

Large scale toxic algae outbreaks

Prolonged heat waves

Prolonged drought

Space weather - geomagnetic risks

Failure or errors of global navigation satellite systems (GNSS)

Tsunami risk

Volcanic eruption

Collapse of Antarctic sea ice

Supernova explosion