Public memorial services to mark the events of last February 22 have taken place throughout the country today.

It's a year to the day that a 6.3 magnitude earthquake shook Christchurch, taking 185 lives.

Today's first public event has been held in Latimer Square next to the site of the CTV building, which collapsed last February killing 115 people.

As people arrived at the memorial service, the NZ Army Band played.

Newstalk ZB's Amanda South says only a few hundred people have turned up, and think the public have recognised this service as a private one for families of the victims.

The service began at Latimer Square with a mihi just before 8:30am.

Christchurch mayor Bob Parker then spoke and says nothing in could've shown Canterbury what was to happen a year ago.

"We had been through one earthquake, it was difficult but we believed we were on a road to recovery, then on this day one year ago everything changed and it will never be the same again."

He has highlighted the spirit of the thousands who helped with the quake response and thanked those who came from afar to help.

Anglican Bishop Victoria Matthews then read selected verses from Psalm 46 before Prime Minister John Key addressed the crowd.

He says February 22 began as just another summer day in Canterbury and people were just going about their business, and at 12:51 everything changed.

"It twisted the buildings, tore up roads, destroyed homes and shook us to the core. Worst of all, it stole 185 loved ones from us."

Mr Key spoke about how Latimer Square was completely different today to how it was a year ago with emergency services everywhere.

"It was a New Zealand I have never seen before."

He's also paid tribute to those who stepped up to help others after the quake.

"People who, despite being personally affected by the quake, dropped everything to help the person beside them or answer the call of duty."

"(The quake) couldn't break the spirit you are famous for."

Mr Key has pledged to build a new Christchurch but says it will take time to recover from the fourth largest earthquake insurance event in the world.

"In part, today is a day to look forward, to dare to dream what a new, vibrant and confident Christchurch will be like, but today is a time to pause and reflect," he says.

"February 22 will forever be one of the darkest days in this proud nation's history, it will also be a day when in the worst of times, the best of human spirit was on display. That spirit is something that no earthquake can ever take away."

Students from St Margaret's College then sang an Irish blessing before Labour leader David Shearer gave a reading.

Representatives of various faith communities offered prayers before Bishop Victoria Matthews gave a final benediction using words from Philippians, and to end the first memorial service, the NZ Army Band led the national anthem.

At 11am the finishing touches were being put in place at North Hagley Park where the main public memorial service to mark the February earthquake was to get underway at midday.

The public began pouring into Christchurch's North Hagley Park and Newstalk ZB's Nicola Grigg says Cantabrians came in their droves, laden with picnic blankets and flowers.

At midday a conch shell was blown and Henare Rakiihia Tau officiated a mihi.

The NZ Army Band led another national anthem before Christchurch Mayor Bob Parker spoke.

He welcomed dignitaries including the Prime Minister, the Governor-General, MPs and other local body representatives, as well as those who have travelled from overseas.

Mr Parker says February 22 is a day that changed things for the city and this has been a year like no other and it's not an easy time for a lot of people.

"There are many unknowns, questions still to be answered, suburbs to be rebuilt, a city to be rebuilt."

He says the quake changed things in the city irrevocably.

"We can never be the same again."

Mr Parker spoke of new links forged between other countries through with what's happened to the city, and says those are bonds that will never be broken.

He then talked of the goodwill directed to Christchurch from within the city, around the country and around the world and says the city will never forget what they have done.

Mr Parker then spoke of the Share an Idea process that turned 106,000 great ideas into a vision.

"A vision that formed a plan and a plan that will shape the foundation for a new future."

Young New Zealander of the Year Sam Johnson then gave a bible reading.

The Christchurch Pops Choir and the NZ Army Band led the hymn 'How Great Thou Art' before Prime Minister John Key read.

Prayers were then led by Police Chaplain Rev Jim Patrick, Hospital Chaplain Rev Pam Tizzard and Fire Service Chaplain Rev James Ullrich.

Young people from the Bahai, Buddhist, Hindu, Jewish and Muslim faiths are now leading an 'Act of Remembrance' before the Linwood College Orchestra performed.

The names of all 185 people who died as a result of the earthquake were then read out by members of the first responders as those in attendance stood as a sign of respect.

At 12.46pm the names of all 185 people had been read out and the nation prepared for two minutes' silence to be led by the Most Rev Barry Jones, the Catholic Bishop of Christchurch.

The nation then fell silent at 12.51pm, as the exact moment a magnitude 6.3 quake struck Christchurch was marked.

At the conclusion of the silence, Most Rev. Barry Jones led a prayer to remember the events of February 22, 2011, those who lost their lives, and those who were evacuated.

Governor-General Sir Jerry Mateparae then gave his address.

At 1.00pm Sir Jerry read a statement on behalf of Prince Charles about the one year anniversary.

"It has been more than 40 years since I first visited New Zealand, and over those many years I have come to know Christchurch and the Canterbury region as treasures of the country's natural and built environment.

"It was, therefore, with rising horror that my wife and I watched the unfolding scenes of devastation that so disfigured this beautiful city and the pain and desolation of those who lost family, friends and colleagues. I can well imagine how the suffering continues to this day for all those who mourn and as you seek to rebuild your lives in the face of this great tragedy. I know that my eldest son was deeply moved by the experiences of those he met who have been so personally and painfully touched by these horrific events.

"At the same time, I know that, as a year has passed, the best of the New Zealand peoples' characteristics have come to the fore. The spirit of determination, of courage and of good humour that so characterizes the people of New Zealand will, I am sure, have held you steady as you go about the slow process of rebuilding your city and your lives. You will know better than me how the bonds of family and friendship and of trials borne together make for strong and resilient communities.

"My wife joins me in extending our continuing and heartfelt condolences to those whose grief may in time ease, but will never fully pass. To those who rebuild day by day, looking to the future with hope, we can only offer you our warmest encouragement and our admiration."

Sir Jerry spoke of the devastation one year ago today.

"Lives were tragically cut short, families were ripped apart, and thousands of homes and buildings were destroyed beyond repair.

"The ripples of that disaster stretched around the world - people in far-flung lands lost loved-ones and grieve too because they never returned."

He then spoke of looking ahead to the future.

"While we remember what occurred, and the grief of those most closely affected, today marks the start of a new day and a new beginning for all of us, and especially the people of Christchurch and Canterbury."

He has compared the future to the life cycle of a butterfly.

"From the shattered cocoon of a once great place, a new and vibrant city can arise."

US Secretary of State Hillary Clinton has sent a message to the people of Christchurch which was then played at the service.

"I had just visited Christchurch a few months earlier and was shocked to learn and see the scope of the damage."

She says they started to work out how the US could help, including sending an urban search and rescue team.

Ms Clinton says when the Japan quake struck, NZ deployed teams of their own.

"We call that paying it forward and that's international relations at its best."

"Christchurch, yes we grieve with you and we think about you all the time," she says.

She says the US looks forward to even more cooperation with New Zealand.

The Linwood College Orchestra then performed 'Nimrod' before a series of interviews with Cantabrians played, highlighting the community spirit, what they love about the city and their hopes for the future.

At 1.26pm, 185 monarch butterflies were released, one for each victim of the earthquake.

Rev Victoria Matthews then gave a blessing.

"For those who have lost loved ones, who have been injured physically, mentally and spiritually, we wish you God's peace."

A number of floral tributes were then placed in North Hagley Park.

Newstalk ZB's Mike Yardley believes around 30,000 to 40,000 have attended today's service.