Xaml Poblemas with ScrollViewer UWP

Scrollview in xaml , to create the interfaces of the applications universal windows 10 UWP, I find a problem with scrollviewer , I cut the text of textblock and the whole scroll of the page does not work, but if I define a value to height of textblock the scroll works perfect.

<Page
    x:Class="AboutThisPattern.MainPage"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:local="using:AboutThisPattern"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    mc:Ignorable="d" RequestedTheme="Light">
   <ScrollViewer Background="White">
        <Grid>
            <Grid.RowDefinitions>
                <RowDefinition Height="1*" />
                <RowDefinition Height="2*" />
            </Grid.RowDefinitions>
            <RelativePanel Grid.Row="0" Background="#FF003D66" RequestedTheme="Dark">
                <Image x:Name="image" HorizontalAlignment="Center" Margin="45,20,219,0" VerticalAlignment="Top" Source="ms-appx:///Assets/Square150x150Logo.png" Stretch="UniformToFill" Width="96" Height="96"/>
                <TextBlock x:Name="textBlock" HorizontalAlignment="Left" Margin="146,20,0,0" TextWrapping="Wrap" Text="App name" VerticalAlignment="Top"/>
                <TextBlock x:Name="textBlock_Copy" HorizontalAlignment="Left" Margin="146,45,0,0" TextWrapping="Wrap" Text="1.0.0" VerticalAlignment="Top"/>
        </RelativePanel>
        <RelativePanel Grid.Row="1">
            <TextBlock x:Name="textBlock1"
                       TextWrapping="Wrap"
                       Height="auto"
                       Text="Lorem ipsum dolor sit amet, consectetur adipiscing elit. Vivamus viverra orci ut erat viverra, eu tempus lacus dictum. Sed vehicula euismod nulla, nec fermentum eros vulputate at. Morbi nec mauris quis augue pretium pulvinar eget vel ipsum. In suscipit nisl eu magna tempor suscipit. Vivamus eleifend imperdiet faucibus. Mauris imperdiet, nunc a elementum aliquam, mi risus tristique lectus, vitae ultricies tortor ligula vitae purus. Vestibulum laoreet a risus eget condimentum. Quisque faucibus, justo vitae dignissim semper, leo augue varius mi, ac maximus tortor magna in massa. Cras tincidunt elit vitae nibh maximus, a pretium nisl efficitur. Cras eros velit, dictum eu posuere vitae, tincidunt ac ipsum. Morbi maximus ultricies purus, sed maximus risus volutpat sed. Vestibulum euismod ante id diam lobortis egestas. Etiam at rutrum augue. Proin facilisis sagittis enim, a sodales nisi feugiat in. Fin de la nota!"
                       Margin="10,20,10,-120.667"/>
        </RelativePanel>
    </Grid>
</ScrollViewer>

If I put that in textBlock1 it does not work Height="auto" but if I put Height=700 you can scroll all over the page, but if you flip it horizontally, too much blank space is displayed. How can I automatically adjust the height that the textblock needs to show its content? Or how would you solve that interface design?