Recently, the 2024 Ice Peak Conference and Youth Science Exploration Activity were launched in Sichuan. The theme of the event is "From science to society: the retreat of the Qinghai Tibet Plateau cryosphere and climate change response". With global warming, the glacier area in the Qinghai Tibet Plateau and surrounding high mountain areas, known as the "third pole of the Earth," is continuously shrinking while the glacier thickness is also thinning. So, how thick are glaciers? How much has it become thinner? How to measure glacier thickness? With these questions in mind, a reporter from Science and Technology Daily interviewed relevant experts. The thickness data has important value. The ocean water on Earth accounts for about 96.5% of the total global water body, while freshwater only accounts for 2.53%. Three quarters of this freshwater is stored in the Antarctic ice sheet, Greenland ice sheet, and mountain glaciers. According to the second China Glacier Cataloging data, there are currently 48571 glaciers in China, with a total area of 51766.08 square kilometers, accounting for approximately 7.1% of the world's glacier area (excluding the Antarctic and Greenland ice sheets). "Glaciers have important scientific and applied values in climate change, water resources management, sea level rise, ecological protection, economic and social development and other fields," said He Xiaobo, associate researcher of the Northwest Institute of Ecological Environment and Resources of the Chinese Academy of Sciences. In the past century, due to the warming of the global climate system, the melting of glaciers and snow has accelerated. The changes in glaciers affect the water cycle process in the surrounding areas, which in turn affects the ecology and environment of the river source areas. "In recent years, the thinning and retreat of mountain glaciers has been a response to climate warming, reflecting the sensitivity of glaciers to climate change." He Xiaobo said that glacier thickness, subglacial terrain, and glacier volume are three important basic parameters of glacier change, and they are also the basic data for research and evaluation of glacier water resources, glacier jumping, and ice core drilling, which are related to glacier reserves, glacier movement, and glacier internal structure. Researchers can use data from ice surface topography and ice thickness measurements to create subglacial terrain, estimate glacier volume, and obtain information on glacier water resource reserves. He Xiaobo said, "Glacier thickness measurement data can provide the thickness values of glacier measurement points and the average thickness of the entire glacier. Researchers can draw topographic maps under the glacier based on this, accurately estimate glacier volume." Monitoring glacier conditions and conducting systematic research on glacier changes have important scientific significance and extremely high application value. In the history of developing measurement tools, on-site core sampling, gravity method, and seismic wave method have been commonly used for glacier detection. But these methods have high work intensity, low efficiency, and poor safety. The Northwest Institute of Ecological Environment and Resources of the Chinese Academy of Sciences has innovated the glacier detection method to make the measurement more accurate. The institute utilized China's independently developed integrated radar for ice and water conditions to comprehensively detect the thickness of the Dongrongbu Glacier on Mount Everest, and successfully obtained glacier thickness data within the range of 6300 to 6500 meters above sea level. The radar used is a ground penetrating radar that can penetrate specific media such as ice and snow. It is an electronic device that uses the characteristics of electromagnetic waves reflected by targets such as ice bed bedrock, ice voids, and internal moraines to discover targets and determine their distance and orientation. He Xiaobo said, in simple terms, it is based on the difference in dielectric constants between ice water and bedrock, and transmits waves through radio waves in ice bodies