澳洲发现世界最长的大陆火山链

Scientists have discovered the world's longest known chain of continental1 volcanoes, running 2,000 kilometres across Australia, from the Whitsundays in North Queensland to near Melbourne in central Victoria. The volcanic2 chain was created over the past 33 million years, as Australia moved northwards over a hotspot in the Earth's mantle3, said leader of the research Dr Rhodri Davies from The Australian National University (ANU).

"We realised that the same hotspot had caused volcanoes in the Whitsundays and the central Victoria region, and also some rare features in New South Wales, roughly halfway4 between them," said Dr Davies, from the ANU Research School of Earth Sciences.

"The track is nearly three times the length of the famous Yellowstone hotspot track on the North American continent," said Dr Davies.

This kind of volcanic activity is surprising because it occurs away from tectonic plate boundaries, where most volcanoes are found. These hotspots are thought to form above mantle plumes6, narrow upwellings of hot rock that originate at Earth's core-mantle boundary almost 3,000 kilometres below the surface.

The study, published in Nature, found that sections of the track have no volcanic activity because the Australian continent is too thick to allow the hot rock in mantle plumes to rise close enough to the Earth's surface for it to melt and form magma.

The research found that the plume5 created volcanic activity only where Earth's solid outer layer, called the lithosphere7, is thinner than 130 kilometres.

These new findings will help scientists to understand volcanism on other continents and from earlier periods in Earth's history, said co-author Dr Nick Rawlinson, now at the University of Aberdeen's School of Geosciences.

1 continental

adj.大陆的，大陆性的，欧洲大陆的

参考例句：

A continental climate is different from an insular one.大陆性气候不同于岛屿气候。

The most ancient parts of the continental crust are 4000 million years old.大陆地壳最古老的部分有40亿年历史。

2 volcanic

adj.火山的；象火山的；由火山引起的

参考例句：

There have been several volcanic eruptions this year.今年火山爆发了好几次。

Volcanic activity has created thermal springs and boiling mud pools.火山活动产生了温泉和沸腾的泥浆池。

3 mantle

n.斗篷，覆罩之物，罩子；v.罩住，覆盖，脸红

参考例句：

The earth had donned her mantle of brightest green.大地披上了苍翠欲滴的绿色斗篷。

The mountain was covered with a mantle of snow.山上覆盖着一层雪。

4 halfway

adj.中途的，不彻底的，部分的；adv.半路地，在中途，在半途

参考例句：

We had got only halfway when it began to get dark.走到半路，天就黑了。

In study the worst danger is give up halfway.在学习上，最忌讳的是有始无终。

5 plume

n.羽毛；v.整理羽毛，骚首弄姿，用羽毛装饰

参考例句：

Her hat was adorned with a plume.她帽子上饰着羽毛。

He does not plume himself on these achievements.他并不因这些成就而自夸。

6 plumes

羽毛( plume的名词复数 )； 羽毛饰； 羽毛状物； 升上空中的羽状物

参考例句：

The dancer wore a headdress of pink ostrich plumes. 那位舞蹈演员戴着粉色鸵鸟毛制作的头饰。

The plumes on her bonnet barely moved as she nodded. 她点点头，那帽子的羽毛在一个劲儿颤动。

7 lithosphere

n.陆界，岩石圈

参考例句：

The hydrosphere and the lithosphere together form the Earth's surface.水圈与岩石圈一起形成地球的表面。

They slide on a more yielding layer at the base of lithosphere.它们在岩石圈底部更柔软的一层滑动。