Como posso configurar o Logback para suprimir toda a sua saída no console (saída padrão)? Em particular, desejo suprimir (ou redirecionar) as próprias mensagens de log do Logback, como as seguintes:

16:50:25,814 |-INFO in ch.qos.logback.classic.LoggerContext[default] - Could NOT find resource [logback-test.xml]
16:50:25,814 |-INFO in ch.qos.logback.classic.LoggerContext[default] - Found resource [logback.xml] at [file:/opt/dap/domains/ap0491/uat1/domain/instance-config/logback.xml]
16:50:25,816 |-WARN in ch.qos.logback.classic.LoggerContext[default] - Resource [logback.xml] occurs multiple times on the classpath.
16:50:25,816 |-WARN in ch.qos.logback.classic.LoggerContext[default] - Resource [logback.xml] occurs at [file:/opt/dap/domains/ap0491/uat1/domain/instance-config/logback.xml]
16:50:25,816 |-WARN in ch.qos.logback.classic.LoggerContext[default] - Resource [logback.xml] occurs at [file:/opt/dap/domains/ap0491/uat1/domain/instance-config/logback.xml]
16:50:25,923 |-INFO in ch.qos.logback.classic.joran.action.ConfigurationAction - debug attribute not set
16:50:25,924 |-INFO in ch.qos.logback.classic.turbo.ReconfigureOnChangeFilter@1a15291 - Will scan for changes in file [/opt/dap/domains/ap0491/uat1/domain/instance-config/logback.xml] every 60 seconds. 

Preciso desabilitar todos os registros na saída padrão porque nosso ambiente de produção impede que os aplicativos imprimam mensagens na saída padrão.

Observe que estou usando o Logback 0.9.21, SLF4J 1.6.0, e nosso aplicativo é executado no WebLogic 10.3.2.