Mt. Pelée doesn't have a single, defined diameter. It's a complex volcano with a variety of features, including:

* A summit caldera: The top of the mountain is a crater formed by past eruptions.

* A volcanic cone: The main structure of the volcano is a cone-shaped mound built up by volcanic activity.

* Lava flows: Lava flows from past eruptions extend outwards from the volcano, covering a significant area.

Therefore, "diameter" could refer to the width of the caldera, the base of the cone, or the area covered by lava flows.

Here's a more specific breakdown:

* Caldera diameter: The caldera at the summit of Mt. Pelée is approximately 1.5 kilometers (0.9 miles) wide.

* Base diameter: The base of the volcanic cone extends for several kilometers, but there's no precise measurement for its diameter.

* Lava flow area: The lava flows from Mt. Pelée cover a significant area on the island of Martinique, but the exact extent varies depending on the specific eruption.

In short, there isn't a single "diameter" for Mt. Pelée. The size of the volcano depends on which specific feature you're referencing.