This study aimed to explore the characteristics and dimensions of of systematic functional gestures employed by pre-service Earth science teachers during instructional sessions. Data were collected from eight students enrolled in a university’s Department of Earth Science Education. The data included lesson plans, activity sheets, and recordings of one class session from participants. The analysis, conducted using the systemic functional multimodal discourse analysis framework, categorized gestures into scientific and social functional dimensions. Further subdivision identified meta gestures, analytical gestures, and interrelated gestures. Additionally, pre-service teachers used gestures to explain scientific concepts, concretely represent ideas and facilitate communication during instruction. This study emphasizes the nonverbal strategies used by pre-service Earth science teachers, highlighting the importance of noverbal communication in teachers’ professional development and the need for its integration into education. It also establishes a systematic conceptual framework for understanding gestures in the instructional context.

1. Introduction
2. Research Questions
3. Theoretical Background
    3.1. Theory of Multiple Representation (TMR)for Gestures
    3.2. Gestures in Teaching and LearningInstruction
    3.3. Systemic Functional Multimodal DiscourseAnalysis for Gestures
4. Research Method
    4.1. Research Procedures
    4.2. Research Participants
    4.3. Data Collection and Analysis
5. Results
    5.1. Exploration of the systematic aspects ofgestures
    5.2. Exploring the functional characteristicsof gestures
6. Conclusions
7. Implications and Discussion
References

• Yoon-Sung Choi(Department of Earth Science Education, Pusan National University, Busan 46241, Korea) Corresponding author