Massive landslides and flash floods on the Nepal-Tibet border have caused widespread damage and left hundreds dead or missing.
Search and rescue operations are under way. Chinese state media has said there are significant casualties, while Nepalese officials anticipate "huge scale loss".
Here is what we know so far.
"Additional analysis of nearby seismic stations, long period seismic waves, and satellite imagery led to the determination that the seismic event was instead a glacial collapse and debris flow, and that no earthquake had occurred," USGS said on Thursday.
Earlier Nepali authorities had also told the BBC that a massive chunk of ice may have collapsed from a mountain, pulling down rocks and other sediments with it.
Climate change is known to be driving faster glacier melt in the Hindu Kush Himalaya region and, as rescue efforts continue, scientists are trying to piece together the exact order of events.
Simon Cook, senior lecturer in energy environment and security at the University of Dundee who specialises in glaciology, said "climate change could have an impact".
He told the BBC "permafrost is partially holding some mountainsides together, this permafrost is warming and thawing and degrading so you are going to get more landslides".
One possibility is that water from rainfall or melting ice may have destabilised the ground or ice, triggering a chain reaction.
Scientist will be looking at satellite images of exactly where the landslide occurred, whether any glacial lakes suddenly drained, and where the river might have become blocked, as well as data on recent rainfall.
A deluge of material careered towards northern Nepalese towns, including areas popular with mountaineering tourists and pilgrims. The border is around 40 miles (64.4km) north of Nepal's capital city Kathmandu.
Footage showed a wall of mud and rock sweeping away buildings, roads and vehicles, as people fled the fast-moving wave of material in the Nuwakot region.
In one video, a towering wall of water and mud was seen rushing down a gorge along the Trishuli River and enveloping the Rasuvagadhi Border check point, a multi-storey building.
Severe flooding has been reported along the Bhote Koshi, Trishuli and Narayani rivers.
Deaths have also been reported in villages on the Tibetan side of the border.
The International Centre for Integrated Mountain Development (ICIDMOD) has warned secondary flooding could occur in the coming days as a result of the debris that washed into the river systems.
In a report, the ICIDMOD said they are in the process of assessing whether the Trishuli River has been temporarily blocked in narrow sections. If it has been blocked, it is at risk of forming a landslide dam - and a second flooding event.
Authorities and scientists are continuing to evaluate the size, location and stability of any potential blockages.
Nepal's prime minister said "the entire nation has been left shocked and deeply distressed" and that officials would coordinate with China on the response.
China's President Xi Jinping urged an "all-out" search effort, and promised stronger monitoring and early warning systems to prevent secondary impacts.
In neighbouring India, Prime Minister Narendra Modi said his government was "prepared to provide Nepal with all possible types of humanitarian assistance".
UN Secretary General António Guterres says he is "saddened by the severe flooding", adding that UN teams and partners are mobilising supplies and personnel in Nepal to support the government-led response.
The US has promised $500,000 (£367,982) in aid which will be used to cover emergency shelter, water, sanitation and other relief items for communities affected by the floods.
UK Prime Minister Andy Burnham said the British government would do "everything we can" to support British nationals in Nepal.
