Earthquakes: What to do

In Australia earthquakes that cause significant damage are extremely rare in the memory of European settlement.

Even though the 5.2 magnitude earthquake centered in Moe Victoria received significant press coverage, there seemed to be no real information on safety during these events. For Australians living on a continental plate earthquakes are quite a mystery. For anyone in Victoria that experienced it, I’d like to say in the general scheme of earthquakes is rather small, and more of a wake up call than anything else. Just enough to crack some walls, drop a few things off shelves in the supermarket and create a few wet pants.

What to do in an earthquake based on where you are when it happens.

General advice:

If you are indoors stay indoors, if you are outdoors stay outdoors. Look for the nearest safe place to take shelter. Don’t try to move too far during an earthquake, as earthquakes get larger its gets quite hard to move at all. Stay away from large glass objects. Avoid large objects that may fall on you.


If you are in doors:

Stay there and look for an internal doorway to stand in, there’s usually enough space to place two adults in a door way. Doorways are extremely strong and will not break easily and provide shelter from falling material.

Find a strong desk or table and get under it. the table should be strong enough for you to drop a 5kg sack of rice on it an be certain it wont break. Remember the table my start to vibrate and move around so you may need to hold onto the legs of the desk, this especially true if the floor is smooth like lino or wood. The biggest hazards you are facing are filling material from the ceiling and breaking glass from the windows. Don’t look at the windows, face away from the windows and and other large glass objects.Stay away from free standing shelves and tall furniture items as they will often fall and/or throw out their contents.

Don’t use elevators or stairs, stay on which ever floor you are on, stairs can collapse and elevator shafts can distort trapping the elevator car between floors.

Before and after an earthquake pets can get pretty crazy. Dogs and cats are often traumatized and may run away, they usually come back after a few days.

Multi-story office  building:

Good luck, as this is one of the worst places to be.

If you are at your desk get under it. If you are walking around, stay close to the center of the building around a support pillar, the real danger is the windows which may all shatter at once. Keep you arms over your head and face, there may be falling ceiling tiles from the false ceiling.  The floors may partially collapse making a dangerous slide to a huge fall. Don’t use the elevator after the earthquake, use the stairs. There is probably an evacuation procedure, follow instruction and assist others. Get out of the general area as soon as possible.

If you are driving:

It may feel like a flat tire or strong wind gusts, that strangely continue when the car has stopped. Pull over to the side of the road. Don’t stop on or under bridges or over passes or near over head power lines or trees, if you can avoid it.

Stop, put the hand brake on, turn on the hazard lights in your car. Turn the car off. Unlock the doors. Stay in the car. Keep your seat belt on. It’s easier to get out of an upturned car than get one off you.

In a park or forest:

Try to move to a clearing (away from trees) and watch for falling branches and trees.


Move away from the shore, wet sand may liquify and become just like quicksand, but stay far from steep sand dunes as they may collapse in miniature land slides. Get ready to leave as soon as its over, earthquakes and tsunamis are related, you need to get 2km away from any water body or 200 meters above sea level. Another reason to move is if you are near an airport that has been damaged some smaller planes may be asked to seek alternative emergency landing spots. Pilots will be looking at beaches and you don’t want a Cessna on your beach towel.

River and lakes:

Rivers and lakes are often on fault lines. If you are in the water get out of the water, the bottom may literally fall out of this water body and you might get sucked to the bottom with it. Similar to taking the plug out of a bath full of water. If the lake or river is within a few kilometers of the sea, a tsunami may roar up the river later on. All kinds of crazy things happen to rivers during earthquakes.

Hot air balloon:

Basically you’re safe but you will need to land before a storm brews up. I  added this because people may be wondering where is a safe place to be during an earthquake and this is one of the few places.


During an earthquake:

Count off seconds in your head or on a watch, firstly it takes your mind off something you cant control and it may give you information about how big the earthquake is and whether its the ‘main event’ or just a ‘warm up’.  An earthquake longer than 60 seconds is going to be very destructive. Try to determine whether the motion you are experiencing is up and down, round and round, side to side, or a series of sudden jolts. this can also give you information about the type of earthquake you are in.

Once the earth quake is over:

Disruption of telephone, electricity, water and sewerage is common in earthquakes. In larger earthquake roads and railway tracks can be damaged.

Find out from radio, internet, TV what the damage was, how big the earthquake was centered and how deep it was. Specifically note if there is damage in your area to telephone, electricity, water and sewerage roads and rail way tracks.

Traditionally radio has been one of the better sources of information on disaster information.

A battery powered radio is very useful for this.

Your home: check for damage to the walls and roof, even if it looks OK it might be unsafe to live in because of structural damage. your roof may be broken and need a tarp to remain waterproof. Damage assessors and engineers will probably start visiting houses to see what is safe and what needs repairs. You may need to call a number to get an appointment or an estimate of when they will arrive to check your house.

If you are at home turn off all non essential electricity, the electricity grid may be damaged and by all of us doing this we are putting less strain on the grid as a whole, reducing further damage.

Keeping just one light bulb on helps you know there is still electricity.

Don’t make unnecessary phone calls the phone grids, wired and wireless may be overloaded. Certainly ring people you care about to tell them you’re OK, and see if they are OK, but keep it brief.

See if your neighbors are OK.

Don’t flush the toilet until you know sewerage systems are operational, not so important if you are not on this grid.

Don’t use tap water until you know the water hasn’t been contaminated, and that this system works.

You may be instructed to boil or add bleach to water for drinking.

Earthquakes can be unpredictable in the way damage is distributed. A great deal of factors (other that the type and magnitude of the earthquake) will come into play, soil type, water table, slope, soil erosion and instability, temperature and the weather. It is quite common for rain and thunder storms to come just after an earthquake, just what you need when your roof is damaged.

Food collecting : Fish traps – Huge atrificial reef

When I started searching for information on fish traps I was originally thing of small traps that could be made from flexible branches or maybe stainless steel mesh.

Certainly a small fish trap would be good if you are traveling to the local river or lake.

Then I saw this:

Fish trap at Poppit sands, Wales UK. 250m long approx.

I was really blown away by the simplicity, permanence, age and scale of this thing.

It’s estimated to be 1000 years old, but no longer able to be used as the boulders have sunken into the sand.

The latest Google earth pictures are taken at high tide and this structure can’t be seen because of that (the original pictures were taken in 2006 at low tide).

But feel fee to search for ‘Poppit sands’ on Google maps

Its worth pointing out that the trap is constructed close to a major estuary and estuaries attract fish.

This type of structure might not work as well if not placed near an estuary. Other important feature are the shallow sloping sandy bottom of the sea bed and the local abundance of rock.

The natural rock reefs attract fish as the tide is lower and a fish swim out of the estuary.

Fish traps were so efficient they were banned from fresh water by the Magna Carta (1215) because they could simply empty the entire river of fish, they were also a hazard to shipping.

Poppit sands fish trap near very large estuary.

So how does it work?

As the tide flows out the water level drops and some fish will be trapped in the artificially constricted reef. Some  modern observers believe that the fish were only netted at the opening apex of the trap.

I suspect that because there are two large opening in the sides of the trap (seeming to be too large for coincidence) the fish may have also been netted there.

Likely people were sent into the trap at low tide to scare the fish into one of the 3 openings, possibly using a moveable drag net in the process.

The other possible reasons for the gaps in the sides of the trap are:

To allow storm surges to move through he trap better and make it less likely to be destroyed in a storm.

To make the wall seem like less of a trap and to make the fish accustomed to swimming through the gap.

Prevent buildup of sand in the trap.

Damage from storm surges that was not intentional.

I have a feeling the construction of this structure would have been a community effort and likely the use of it would have been a community activity, certainly the number of fish caught could have easily fed a village.

If you consider at each of the three openings, two people holding the net and one collecting the fish in baskets, you are looking at a minimum of nine people not including the fish scaring and the transporting of the baskets to shore.

How to make one?

I’m really not sure and I’ll have to research this some more.

my speculation so far:

As even light rock weight about 2700 Kg per cubic meter, It’s not going to be easy to move these boulders very far easily, so a the local source of rock is key. Perhaps the local river system was used to transport the rock from upstream.

Of course moving things heavy on water is easier because of boast and rafts, and submerged rock looses some weight due to buoyancy. so perhaps the rocks were suspended in the water and moved with boats and rafts or possibly rolled into position under water using logs and smaller rocks as pivots and levers. I suspect the proximity of the river would have meant there would have been boats available. Nothing attracts boats like a river mouth or estuary.

Which part to build first?

Apex stones first? place furthermost stones in water first and work your way back to the shore?

Start at the shore and use the out going current to assist dragging the rest of the boulders into place?

Utilization of leeward scour?  A solid rock place on sand will create a scoured out depression in the turbulent current leeward (down current) from the rock, eventually the depression will become so large the rock will roll in this depression.

If the slope of the floor is correct and the rock if roundish, it will continue to roll until it falls into the depression created by another rock. If the walls closet to the shore were created first the rest of the rock might have just been dumped in the trap and the natural out going current could have done a lot of the work.

Cost: a lot of time, rocks and cleverness and probably boats. Having people scratch their heads a thousand years later, priceless…

Oil And GDP

Really stunned when I found this, I have suspected this for some time but there it is.

Analysis and explanation:

the world GDP: a measure of the total value of economic activity. The solid line is showing the percentage increase in world GDP. Remember that the current economy depends on perpetual growth to survive.

Oil production growth: the increase in supply of oil.

this chart draws a strong relationship between these to indicators. th implication is world GDP growth can only be sustained with continual increases to OIL supply. Still having oil or producing the same amount as last year is not enough to support the current economic system.

If we are right in our belief that peak oil has happened or will happen very soon, this will mean the world GDP will decrease and nothing can be done to stop this decline. Frightening really, it seems not matter where i look I’m seeing the same fact manifest in slightly different forms but none the less the same facts.

Gold and Oil:

Gold to oil ratio. How may barrels of Oil (159 L) can be traded for 1 ounce (31.01g) of Gold.

<add a chart of  ounce of gold vs barrel of oil ratio for a similar time period an back to 1960’s if possible>

Gold has been used to measure the value of oil for some time. Gold is used because unlike fiat currency it can’t be created out of thin air and requires significant human effort to acquire. Gold has much history as a currency and has a relatively stable value over time against many other humanly desirable things. Using Gold as a measure of the value of oil allows use to see the price of oil without the price distorting effects of fiat currency. If we used a currency that went into hyperinflation to measure the price of oil we would see more the effects of a worthless currency that of an expensive oil. This chart seems to back up the other chart we are living in a time of expensive oil. There seems to be along tern trend (from about 1986) that Oil is becoming progressively more expensive.

For those into politics you might note that Bush (I) and Clinton were in the time of cheap Oil, whereas Bush(II) and Obama were in the era of expensive Oil.

12 Volt Sealed Lead Acid battery

Also called the SLA.

Very similar to the flooded battery except the acid has had a gel added to it to make it more or less solid and the pressure release lids are no longer needed.

A wide variety of capacities.


Update there is a thory that a SLA battery can be reconditioned by charging and then discharging (fast) about 10 times.

I have tried this technique with a few 6 Volt batteries with variable success, some batteries recharge and then begin to hold charge others are simply to damaged internally.


This became relevant for me as i recently found a large capacity 12 volt SLA and I’m attempting to recondition it using a battery charger and a 50W halogen bulb for discharging and I’m currently at the second discharge cycle.


So with a 50W bulb how much current will I be using?

P= V x I

50W = 12 V x ?A

50/ 12 = ?A

4.16 = A

Wires rated for 10A so no problem.



<pictures of SLA and cross section diagram>

A more portable version of the car battery weighing in at 1.5 Kg for a 7.2 amp hour battery.

Cost $25 for 7.2 Amp hour battery

Electrical Energy: The Inverter

400W 12V inverter with alligator clips and aluminum housing/heat sink. 240V 10A 50Hz

Simply put: the Inverter changes DC current into AC current.

Usually the voltage and frequency output are based on household AC but other voltage/frequency combos are possible.

Some inverters made for AC motors such as electric bicycles produce variable frequency 3 phase AC.

Because of the high current and voltage and current (240V 10A) produced by Inverters they are extremely dangerous.

Inverters are rated for a certain wattage output so when plugging in a device into an inverter check to make sure the inverters total wattage is not being exceeded.

Inverters usually make a alarm tone when they are running low on current, which is usually the sign the battery they are connected to is almost drained of current.

Inverters are quite inefficient with losses of 50% on inversion being typical.

If you have battery banks use DC wherever possible to effectively double your usable energy.

Some newer inverters are designed with a cigarette plug as the DC power connector.

these cannot be used for more than 150W rated devices because of the limitation of current flow through the cigarette plug.

For power consumption greater than 150W use large size alligator clips or heavy gauge battery terminal connectors.

Inverters are sold as square wave, modified sine wave or pure sine wave.

pure sine wave inverters are the most expensive and the extra expense (normally double the price of a modifies sine wave model of the same wattage) are only really noticed in some  Hi-Fi and television equipment.

If the device you are plugging into an inverter contains a rectifier, the exact shape of the wave matters less at the wave is being recitficed to DC, so a modiifed sin wave would be perfectly acceptable here.

square wave inverters are acceptable for very simple application such as incandescent bulbs.

Inductive load

Devices such as fluorescent lights and some devices with large motors such as some fridges have high inductive load and must be either modified before inverters are used or not used at all.

<check this>

grid connect