This issue covers the papers on two special themes: (1) Mineral resources from deep sea—Science and Engineering and (2) Planning and development of underground space and infrastructure for sustainable and liveable cities.

The special theme of “Mineral resources from deep sea—Science and Engineering” is on the exploration and transport of mineral resources from deep sea. The mineral resources are rich in deep sea and their rational development and utilization can meet the needs of social and economic development. The security and strategy of deep-sea mineral resource exploration are important to the successful development of high-quality marine economy. However, deep-sea science and mineral resource exploitations confront many unknowns. This special theme aims to provide a platform for the exploration and exchange in research and engineering progresses and six papers were received, including four Original Research Papers, one Review Paper, and one Short Communication. The authors are from Australian Catholic University, National University of Singapore, Ocean University of China, China University of Mining and Technology, and so on.

The idea for this special theme originates from the First Young Scholars Symposium on Deep-Sea Science and Mineral Resources (2022). Deep Underground Science and Engineering (DUSE) collaborated with the conference organizer and launched a call for a special theme: Mineral Resources from Deep Sea—Science and Engineering. Guest Editors of this special theme are Prof. Jianhua Yue (China University of Mining and Technology), Prof. Yonggang Jia (Ocean University of China), Prof. Chunhui Tao (Second Institute of Oceanography, Ministry of Natural Resources, China), Prof. Haiyan Yang (China University of Mining and Technology), Prof. Honglei Shen (China University of Mining and Technology), and Prof. Zhuangcai Tian (China University of Mining and Technology).

The special theme of “Planning and development of underground space and infrastructure for sustainable and liveable cities” is on city development from the prospects of underground space and infrastructure. The utilization of urban underground space for accommodating urban functions, through developing underground commercial, transport, and public infrastructure, has been a common practice in urban development in past decades. Increased migration of populations to cities brings many urbanization problems, such as inadequate land and infrastructure, air and noise pollution, traffic congestion, and degraded environmental quality, thus providing an opportunity for underground infrastructure as an attractive solution to these problems. As a relatively new dimension of cities, underground space has been widely recognized as a valuable resource for city development. Urban underground space utilization is an effective way of developing and redesigning cities, promoting sustainable urban development, and building liveable cities. Underground infrastructure has considerable impacts on land use, social, environmental, and economic development, and urban sustainability. These are important topics to be explored. Further, underground space and infrastructure developed in different urban settings may have unique characteristics that require further investigation.

This issue covers four research papers on this special theme: two papers from this special theme call and two papers from conventional submission. We put them together to share similar knowledge. The Guest Editors for this special theme are Dr. Jianqiang Cui, Griffith University, Australia; Dr. Miaocheng Weng, Chongqing University, China; and Dr. Dong Lin, University of Aberdeen, United Kingdom.

DUSE is grateful for the efforts from the guest editors and extend special thanks to all authors and editors. We are expecting to collaborate with all of you on interesting and hot topics for Deep Underground Science and Engineering in the future.