surface: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On CentOS possible default full paths are:

/usr/bin/surface - from package: GMT

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/lib/gmt/bin/surface - from package: GMT

You may install the required package with command apt-get install {package}

Error in other languages:
surface: bevel nie gevind nie
surface: comandă negăsită
surface: comando não encontrado
surface: commande introuvable
surface: command not found
surface: käsku ei ole
surface: không tìm thấy lệnh
surface: komanda nerasta
surface: Kommando nicht gefunden.
surface: kommandot finns inte
surface: komut yok
surface: nie znaleziono polecenia
surface: níor aimsíodh an t-ordú
surface: no se encontró la orden
surface: no s'ha trobat l'ordre
surface: opdracht niet gevonden
surface: parancs nem található
surface: perintah tidak ditemukan
surface: príkaz nenájdený
surface: příkaz nenalezen
surface: команда не найдена
surface: командата не е открита
surface: 命令找不到
surface: コマンドが見つかりません