China's icebreaker and polar research vessel Xue Long arrives at Lyttelton Port in Christchurch, New Zealand, January 16, 2015. Xue Long arrived at Lyttelton Port in Christchurch on Friday. It would dock at Lyttelton for refuelling and cargo transfer after travelling through the Southern Ocean from Antarctica's Ross Sea region. Photo: Xinhua

China's icebreaker and polar research vessel Xue Long docks at Lyttelton Port in Christchurch, New Zealand, January 16, 2015. Xue Long arrived at Lyttelton Port in Christchurch on Friday. It would dock at Lyttelton for refuelling and cargo transfer after travelling through the Southern Ocean from Antarctica's Ross Sea region. Photo: Xinhua

China's icebreaker and polar research vessel Xue Long arrives at Lyttelton Port in Christchurch, New Zealand, January 16, 2015. Xue Long arrived at Lyttelton Port in Christchurch on Friday. It would dock at Lyttelton for refuelling and cargo transfer after travelling through the Southern Ocean from Antarctica's Ross Sea region. Photo: Xinhua

A local media reporter films China's icebreaker and polar research vessel Xue Long approaching Lyttelton Port in Christchurch, New Zealand, January 16, 2015. Xue Long arrived at Lyttelton Port in Christchurch on Friday. It would dock at Lyttelton for refuelling and cargo transfer after travelling through the Southern Ocean from Antarctica's Ross Sea region. Photo: Xinhua

China's icebreaker and polar research vessel Xue Long arrives at Lyttelton Port in Christchurch, New Zealand, January 16, 2015. Xue Long arrived at Lyttelton Port in Christchurch on Friday. It would dock at Lyttelton for refuelling and cargo transfer after travelling through the Southern Ocean from Antarctica's Ross Sea region. Photo: Xinhua