MtGox API - What is ticker volume value?

[BkkCoins]

I'm using the MtGox ticker API to pull some values.

https://mtgox.com/api/0/data/ticker.php

currently returning: "vol":116931

But according to BitcoinCharts site USD volume is 192,906.82 USD and BTC volume is 31,012.2065734 BTC.
On it's "Trade History" page is has another value for BTC 1 day volume: 112,799.89

So are these just wrong? Or is the API "vol" some other figure, calculated differently?

Does someone know definitively what that vol figure is?

I'm guessing it's 24 hour BTC volume and it just gets out of sync with other values around.

[kostas]

I also have the same question, if somebody knows more details about what this vol value represents please give a hint.
Thank you,