中文摘要：

腾冲位于青藏高原东南缘印度与欧亚大陆碰撞边界,是中国最年轻的火山区之一.全新世以来的火山主要分布在腾冲盆地的中央,由北向南形成一个串珠状的火山链.为了研究这一地区的壳内岩浆活动以及与火山分布的对应关系,我们在腾冲盆地开展了为期一年的流动地震观测,利用记录的远震波形和接收函数方法反演了台站下方的S波速度结构.结果表明,打鹰山、大-小空山、黑空山存在一个相互联通的岩浆囊,它的深度为6~15 km,南北方向宽约16 km;火山湖具有一个相对独立的岩浆囊,它的深度为9~16 km,南北方向小于8 km,上述两个岩浆囊的深部热流通道位于黑空山与火山湖之间.在测线南端,老龟坡火山下方的低速特征十分突出,岩浆活动集中在10~25 km深度之间,有可能受到大盈江断裂与腾冲火山断裂相互交汇的影响,它与邻近的马鞍山属于另一个岩浆存储系统.火山区的莫霍面深度在38~41 km之间,在大-小空山下方出现局部抬升,部分台站的壳幔边界具有过渡带性质并呈开放状,有可能成为热流物质由地幔进入地壳的上升通道.

英文摘要：

Tengchong is a young volcanic area near the Euro-Asian collision boundary in the southeastern Tibetan margin. Holocene volcanoes are mostly concentrated in the center of the Tengchong basin, where they construct a string-like volcanic cluster along the north-to-south direction. In order to study the magma activity and its relation with the volcanic distribution, we deployed a temporary earthquake observation within the Tengchong basin. The survey line is approximately 40 km long between the Heshui town in the south and the Gudong town in the north, passing through the Laoguipo, Dayingshan, Dakongshan, Xiaokongshan volcanoes and the Crater Lake. Broadband seismic instruments were installed at nine stations with an average 4 km spacing. The observation operated for a period of 14 months from May 2015 to July 2016. According to the Chinese Earthquake Bulletins, we selected 61 teleseismic events with magnitudes greater than Ms 5.0 and distance ranges between 30° and 90°. They include 1 Ms≥8.0 event, 9 Ms≥7.0 events, 49 Ms≥ 6.0 events, 2 Ms≥5.0 events. Most of the events were located in the western Pacific region, however, they were very rare in west of the study area. Finally, 612 teleseismic waveforms are obtained from the recoding data at nine stations. A time-domain deconvolution technique is employed to compute receiver functions, in which the maximum entropy as the rule to determine auto-correlation and cross-correlation functions is used to calculate receiver functions. The advantage of this is to extract valid signals that are overwhelmed by background noise. The length-scale of seismic structure is sensitive to the waveform frequency, thus two Gaussian filters（1.0 and 2.5） were applied to constrain the receiver functions. The former is used to extract large-scale velocity structures and the latter to resolve detailed structures. Due to the low signal/noise ratio for receiver functions with G2.5, they are not used in our inversion. The neighborhood algorithm（NA） was used for the receiver func