If you only have a minute and you want today's need-to-know earthquake news at a glance, this is the page for you.

1. State of Emergency extended

The city of Christchurch has extended its State of Emergency by a week.

It was to cease at midday today, but Civil Defence has decided that many structures around the city remain in far too unstable a condition for human occupancy.

Christchurch Mayor Bob Parker has called for calm as aftershocks continue to hit Canterbury.

Seismologists have said the tremors may continue for a week or more.

2. Aftershocks 'violent', but major damage avoided

No 'substantial' damage had been inflicted by the hefty aftershocks that hit the city this morning, according to the region's Civil Defence director.

Aftershocks of up to magnitude 5.1 were recorded steadily though the morning, stretching the already frazzled nerves of residents and relief workers.

Some inspected buildings will require re-assessment but an initial check showed no major damage caused today, said Civil Defence Director, John Hamilton.

The weather forecast through to Thursday is for cool conditions and patchy rain, returning to mainly fine conditions after Friday morning.

3. Trauma counselling on the way

The Government understands well that the hurt suffered in the earthquake and the persistent aftershocks is not purely physical.

Today, Social Welfare Minister Paula Bennett announced the Government has set aside $2.4 million for trauma counselling for Christchurch earthquake victims.

She says 34 counsellors from across New Zealand would head to the quake-stricken city today.

4. Vital road tunnel closes, then reopens

The Lyttelton Tunnel has reopened after a temporary closure, for safety reasons.

The New Zealand Transport Agency (NZTA) closed the tunnel at around 9am after this morning's big magnitude 5.1 aftershock.

The tunnel was thoroughly checked and three hours later NZTA Canterbury manager Peter Connors said while there is superficial damage, it's safe to use.

5. Message of sympathy from Buckingham Palace

Queen Elizabeth II has been in contact with Prime Minister John Key to pass on her support for quake-stricken Cantabrians.

A spokesperson from Buckingham Palace said: "The Queen has today asked the New Zealand Prime Minister to send her good wishes to those affected by and helping with the aftermath of Saturday's earthquake in Christchurch."