Keyframe animation key time

I've just created a keyframe animation like this:

[UIView animateKeyframesWithDuration:10 delay:0 options:0 animations:^{
    [UIView addKeyframeWithRelativeStartTime:0 relativeDuration:.1 animations:^{
        view.alpha = 0;
    }];
} completion:nil];

And this is a CAKeyframeAnimation that gets created:

(lldb) po [self.layer animationForKey:@"opacity"]
<CAKeyframeAnimation:0x10a6364b0; keyTimes = (
    0,
    "0.1",
    1
); values = (
    1,
    0,
    0
); calculationMode = linear; delegate = <UIViewKeyframeAnimationState: 0x10a6358d0>; fillMode = both; timingFunction = easeInEaseOut; duration = 10; keyPath = opacity>

Question:

The entire animation should take 10 seconds with the opacity animating for 10 * 0.1 = 1 second, right? When I look at the animation, the change is being animated way longer than 1 second.

Why?