Jenson Button's final day of pre-season testing proved to be more fraught than he had imagined after girlfriend Jessica Michibata was caught up in the earthquake that hit Japan on Friday.

Michibata was taking part in a photoshoot in Tokyo when the quake, the worst to hit Japan for well over 100 years, hit off the coast near the city of Sendai.

It meant Button was forced to climb into his McLaren to start Friday testing in Spain unaware of whether Michibata was okay after shocks from the quake were felt in the Japanese capital and he admitted his thoughts were with those caught up in the disaster.

"I couldn't speak to the missus, to Jessie, because the phone lines weren't working in Japan," Button was quoted by Planet-F1. "So halfway through the day, the only way I could get in touch with her really was through Twitter. I found out that she was okay. She then sent me a text saying 'How's testing going?' It was like 'Honey, that's not really the most important thing at the moment. How are you? How are you feeling?'

"She's fine, very shaken. She was in Tokyo doing a photoshoot in a studio underground so it was pretty horrific. I think the whole of Tokyo was pretty shaken.

"It's pretty horrendous, devastating and it's bad for Tokyo, but really bad for Sendai. A tsunami there has wiped out most of it. It's horrific footage you'll probably see on TV, so my heart and thoughts go out to all of the people affected.

"Motorsport is one thing, but something like that happening is so much bigger than the problems we have here today."