Havre Trough

The Havre Trough (also known as the Havre Basin) is an actively rifting back-arc basin situated between the Australian Plate and the Kermadec Plate. It lies approximately 100 km (62 mi) to 120 km (75 mi) wide and extends northward from New Zealand's Taupō Volcanic Zone, continuing into the Lau Basin to the north.

 Geology 
The Havre Trough is a rifting domain characterized by basins up to 3.7 km (2.3 mi) deep in the south, with volcanic edifices rising to within 2.5 km (1.6 mi) of the ocean surface. The rifting is oblique to the bounding ridges and features horsts, grabens, and extrusive magmatism. Its western boundary is marked by the remnant Lau-Colville Ridge, and its eastern boundary by the active volcanic Kermadec Ridge.https://ruor.uottawa.ca/bitstream/10393/43523/3/Gray_Alexandra_2022_thesis.pdf

The basin shows evidence of active extension, especially in its eastern basins, which have high heat flow and shallow seismicity. Further south, the Ngatoro Rift and Rumble Rift are key tectonic features associated with ongoing rifting.

 Tectonic Activity 
The extension rate in the Havre Trough varies between 15 mm (0.59 in)/year and 25 mm (0.98 in)/year, increasing northward toward the more rapidly spreading Lau Basin. The area also experiences volcanic activity, especially along the Kermadec Ridge.

 Related pages 

 Lau Basin
 Kermadec Trench

 References 

Category:Geography of Australia